CN105046093A - Yarn track solving method based on spindle with random section in ring-shaped knitting - Google Patents

Abstract

The present invention relates to a yarn track solving method based on a spindle with a random section in the ring-shaped knitting. According to the yarn track solving method, initial coordinates of yarn fall points and contacts on a guide ring are automatically set according to input initial parameters and a yarn track is obtained by a four-step algorithm of solving projection points, solving intersection points of lines, screening qualified fall points and searching adjacent surfaces. Meanwhile, in order to enable simulation to further accord with the fact, i.e. keep synchronism of the yarn fall points and the contact points on the guide ring in the rotating direction, an adaptive time step algorithm is also added. Finally, an important parameter braid angle of the yarn track is solved by two adjacent fall points of the yarn track. According to the present invention, accurate solution of the yarn track can be carried out aiming at the spindle with the random section in the ring-shaped knitting and finally, yarn track discrete data is imported into post-processing software to check effectiveness of a result by visualization; and by the mode, accuracy and mechanical properties of an object formed by braiding can be greatly improved.

Description

A kind of yarn track method for solving of the arbitrary section mandrel based on annular weaving

[technical field]

The present invention relates to a kind of computing method of yarn track, be specifically related to a kind of yarn track method for solving of the arbitrary section mandrel based on annular weaving, belong to weaving weaving technology field.

[background technology]

Annular weaving is a kind of ancient technology.Due to the mechanical characteristic of the integrated high-performance textile of annular weaving, so this kind of compound substance has been widely used in the fields such as Aeronautics and Astronautics, automobile, shipbuilding, the parts applied have had: properller blade, rocket larynx lining, wind power generation wing, carbon fiber bicycle frame and automobile component etc.

Along with the application demand of annular weaving compound substance develops to breadth and depth, annular weaving process technology is also popularized in the factory.But major part processing is common tubular shape knitting forming thing, and the prediction locus method of mandrel not a kind of effective Quick-forming of arbitrary section that the mandrel of complexity is lived.This also gives to manufacture to process and brings very large trouble, owing to there is no effective simulation means, usually there will be some beyond thought mistakes in processing, these mistakes make working (machining) efficiency extremely low just, differing widely of the precision of the knitting forming thing obtained and mechanical property and expection.

Therefore, for solving the problems of the technologies described above, the necessary yarn track method for solving providing a kind of arbitrary section mandrel based on annular weaving of innovation, to overcome described defect of the prior art.

[summary of the invention]

For solving the problems of the technologies described above, the object of the invention is to a kind of yarn track method for solving of the arbitrary section mandrel based on annular weaving, its mandrel for arbitrary section carrys out accurately predicting yarn track, greatly can improve precision and the mechanical property of knitting forming thing.

For achieving the above object, the technical scheme that the present invention takes is: a kind of yarn track method for solving of the arbitrary section mandrel based on annular weaving, and circular knitting machine comprises spooler, mandrel, yarn, spindle, guide ring and big disk; Setting mandrel coiling speed is left set to alphabetical V, and spindle rotational angular velocity is set to ω _s, guide ring radius is R _g; The point that yarn contacts with guide ring is set to q, and the point that yarn contacts with mandrel is called drop point p, and yarn drop point is set to H to the distance of guide ring ₀, the contact point angular velocity of yarn on guide ring is also ω _s; It comprises the steps:

1), the surface segmentation by an arbitrary section mandrel: first in a rotational direction mandrel is divided into the dry rectangular blocks of promise, more axially according to certain axial step-length even partition, the diagonal line finally connecting each rectangle obtains minimum unit triangle gridding; Wherein each rectangular blocks occupies an angle ω in a rotational direction _s;

2), the initial drop point p of every one thread is set ₀with the initial contact point q on guide ring ₀;

3), preset time step delta t, according to angular velocity omega _scontact point q on next guide ring just can be obtained with coiling speed V ₁, and be q ₁at initial drop point p ₀subpoint q ' on the Triangular object model of place ₁, then connect subpoint q ' ₁with initial drop point p ₀can meet at a certain bar limit of this triangular facet thus obtain intersection point, this intersection point is exactly next drop point p ₁; Reusability said method obtains all drop points of yarn, thus forms a track;

4), after yarn track is tried to achieve, by two adjacent yarn impact point calculation braid angles, formula is as follows:

$\mathrm{\α}=\left|\arccos \frac{\stackrel{\→}{n_1}\·\stackrel{\→}{n_2}}{\left|\stackrel{\→}{n_1}\right|\·\left|\stackrel{\→}{n_2}\right|}\right|;$

Wherein the vector of the line of two adjacent drop points, denotation coordination z-axis is projected in the vector on two adjacent drop point place Triangular object model.

The yarn track method for solving of the arbitrary section mandrel based on annular weaving of the present invention is further: described spooler pulls mandrel toward left movement; Two groups of spindles do clockwise and counterclockwise movement around big disk center respectively, so yarn also does clockwise and counterclockwise movement.

The yarn track method for solving of the arbitrary section mandrel based on annular weaving of the present invention is further: described step 2) concrete grammar as follows: the initial angle of given n-th one thread meet following condition: find this rectangular blocks position, yarn initial point place; Wherein, angle with two end points according to leg-of-mutton wherein two summit projection formation rectangular blocks any in rectangular blocks obtain; Then from true origin along angle the line doing two end points of straight line and rectangular blocks produces an intersection point, and this intersection point is exactly the initial drop point p of this yarn ₀;

Other yarn uses formula:

Obtain initial angle, and initial drop point p can be obtained ₀;

Be uniformly distributed on 360 °, a circle according to number of yarns, obtain all yarns equally distributed initial contact point q on guide ring ₀.

The yarn track method for solving of the arbitrary section mandrel based on annular weaving of the present invention is further: described step 3) in, time step Δ t adopts following methods to obtain: given N _tan initial value 1, namely assert yarn through the Triangular object model quantity required for a rectangular blocks be 1; Given N _tvalue after, according to formula obtain the value of time step.

The yarn track method for solving of the arbitrary section mandrel based on annular weaving of the present invention also can be: described step 3) in, whether yarn drop point site accurately adopts with the following method: by calculating the distance between the end points in yarn drop point and rectangular blocks, if distance is 0, just illustrates and reach border; Simultaneously the Triangular object model number of yarn process or time step long number are designated as N ' _t; N ' _twith N _tvalue compare, if unequal, given N is described _tinitial value incorrect, at this moment at N _tinitial value on add 1, recalculate the drop point of yarn in this rectangular blocks; Until N _twith N ' _tvalue equal till.

Compared with prior art, the present invention has following beneficial effect: the yarn track method for solving of the arbitrary section mandrel based on annular weaving of invention can carry out accurately predicting yarn track for the mandrel of arbitrary section, check simulation result validity or by importing yarn track discrete data assay validity, greatly can improve precision and the mechanical property of knitting forming thing.

[accompanying drawing explanation]

Fig. 1 is the schematic diagram of circular knitting machine.

Fig. 2 is the realistic model figure of single yarn.

Fig. 3 is the stress and strain model mode figure of mandrel.

Fig. 4 is that the initial drop point of yarn arranges figure.

Fig. 5 is the theoretical nomogram of yarn drop point.

Fig. 6 is implementation algorithm figure in yarn impact point calculation machine.

Fig. 7 is Problems existing figure under yarn friction speed.

Fig. 8 is that braid angle solves figure.

The process flow diagram of the yarn track method for solving of Fig. 9 arbitrary section mandrel based on annular weaving of the present invention.

[embodiment]

As shown in Figure 1, the present invention uses object to be circular knitting machine with complicated mandrel, forms primarily of spooler 1, mandrel 2, yarn 3, spindle 4, guide ring 5 and big disk 6.Wherein spooler 1 pulls mandrel 2 toward left movement.Two groups of spindles 4 do clockwise and counterclockwise movement around big disk 6 center respectively, yarn 3 left end is fixed on mandrel 2 left end, and yarn 3 right-hand member is wrapped in these two groups respectively and takes on yarn device (not shown), so yarn 3 also rotates along with taking yarn device and does clockwise and counterclockwise movement.

For the circular knitting machine of so a kind of Quick-forming, in simulations, it is reduced to realistic model as shown in Figure 2 by the present invention.First mandrel 2 coiling speed is left set to alphabetical V, and spindle 4 rotational angular velocity is set to ω _s, guide ring radius is R _g.Then the point that yarn 3 contacts with guide ring 5 is set to q, and the point that yarn 3 contacts with mandrel 2 is called drop point p, and yarn 3 drop point is set to H to the distance of guide ring 5.Simultaneously in order to can be easier analysis, have ignored all frictions and contact the impact disturbed.And think that yarn is a line not having cross section.Therefore have ignored all frictions and can to think after the impact contacting interference that spindle 4 move on big disk 6 synchronous with contact point on yarn 3 and guide ring 5, namely big disk can be ignored in realistic model, the contact point angular velocity at this moment on guide ring 5 is similarly ω _s.In fig. 2, the angle of yarn 3 and mandrel 2 center line is set to braid angle α finally.Braid angle is the validity that an important parameter of fabric construction is used for checking simulation result.

The input parameter that the present invention needs comprises: number of yarns N _y, angular velocity omega _s, coiling speed V, guide ring radius R _gand initial convergence zone length H ₀.Numerical method of the present invention is as follows:

First the surface segmentation of an arbitrary section mandrel is become as shown in Figure 3.First in a rotational direction mandrel is divided into the dry rectangular blocks of promise, in the axial direction according to certain axial step-length even partition.The diagonal line finally connecting each rectangle just can obtain minimum unit triangle gridding.Wherein each rectangular blocks occupies an angle in a rotational direction

Then the initial drop point p that every one thread is set is needed ₀with the initial contact point q on guide ring ₀.The initial angle of first given n-th one thread (as shown in Fig. 4 left view), meets following condition:

Just can find this rectangular blocks position, yarn initial point place.And angle with can obtain according to two end points of any leg-of-mutton wherein two the projection formation rectangular blocks of summit in left view in rectangular blocks in front view, these data are all included in stl file.Then from true origin along angle the line doing two end points of straight line and rectangular blocks produces an intersection point, and this intersection point is exactly the initial drop point p of this yarn ₀.Formula below only need be used to obtain initial angle for other all yarns, just can obtain initial drop point,

Which is be uniformly distributed on 360 °, a circle according to number of yarns in fact.Use formula (2) above can obtain all yarns equally distributed initial contact point on guide ring equally.

As shown in Figure 5, preset time step delta t, according to angular velocity omega _scontact point q on next guide ring just can be obtained with coiling speed V ₁, and be q ₁at initial drop point p ₀subpoint q ' on the Triangular object model of place ₁, then connect subpoint q ' ₁with initial drop point p ₀can meet at a certain bar limit of this triangular facet thus obtain intersection point, this intersection point is exactly next drop point p ₁.This method of Reusability just can obtain all drop points of yarn, thus forms a track.

Four discrete equations below adopting in above-mentioned algorithm.

$\left(\begin{array}{c}{q}_{n+1}^x\\ q_{n+1}^y\\ q_{n+1}^z\end{array}\right)=\left(\begin{array}{c}{R}_g\·sin\left(Arc\tan \right(\frac{q_n^x}{q_n^y})+k\·{\mathrm{\ω}}_s\·\mathrm{\Δ}t)\\ R_g\·\cos \left(Arc\tan \right(\frac{q_n^x}{q_n^y})+k\·{\mathrm{\ω}}_s\·\mathrm{\Δ}t)\\ q_n^z+V\·\mathrm{\Δ}t\end{array}\right)---\left(3\right)$

This formula shows the relation on guide ring between next contact point and current contact point, due to known initial contact point, so all contact points can use formula (3) to try to achieve.

$\left(\left(\begin{array}{c}{p}_n^x\\ p_n^y\\ p_n^z\end{array}\right)-\left(\begin{array}{c}{q}_{n+1}^{\′x}\\ q_{n+1}^{\′y}\\ q_{n+1}^{\′z}\end{array}\right)\right)\·\left(\left(\begin{array}{c}{q}_{n+1}^x\\ q_{n+1}^y\\ q_{n+1}^z\end{array}\right)-\left(\begin{array}{c}{q}_{n+1}^{\′x}\\ q_{n+1}^{\′y}\\ q_{n+1}^{\′z}\end{array}\right)\right)=0---\left(4\right)$

This formula shows that the line of yarn drop point and subpoint must be perpendicular with the line of the contact point on guide ring and subpoint.

$\left(\left(\begin{array}{c}{p}_n^x\\ p_n^y\\ p_n^z\end{array}\right)-\left(\begin{array}{c}{p}_{n+1}^x\\ p_{n+1}^y\\ p_{n+1}^z\end{array}\right)\right)=\mathrm{\λ}\·\left(\left(\begin{array}{c}{p}_n^x\\ p_n^y\\ p_n^z\end{array}\right)-\left(\begin{array}{c}{q}_{n+1}^{\′x}\\ q_{n+1}^{\′y}\\ q_{n+1}^{\′z}\end{array}\right)\right)---\left(5\right)$

Wherein λ is arbitrary constant.This formula shows that the current drop point of yarn must be identical with the line direction of the current drop point of yarn and next drop point with the direction of the line of subpoint.

$Q\left(L\left(\begin{array}{c}{p}_{n+1}^x\\ p_{n+1}^y\\ p_{n+1}^z\end{array}\right)\right)=0---\left(6\right)$

Wherein Q represents mandrel surface function, and L represents the function on certain limit on Triangular object model.This formula shows that yarn drop point one fixes on certain limit of the Triangular object model of mandrel surface.

By program language, it can be realized in a computer based on four discrete equations.As Fig. 6 illustrates the detailed algorithm how realized in a computer.Straight lines all in a program and face equation all use two general expressions below:

A·x+B·y+C·z+D＝0(7)

$\frac{x-x_0}{m}=\frac{y-y_0}{n}=\frac{z-z_0}{l}---\left(8\right)$

In a of Fig. 6, formula (7) and formula (8) is first used to obtain subpoint.In the b of then Fig. 6, formula (8) is used to obtain the intersection point of line and line, because Triangular object model has three limits, so produce three intersection point g _ab, g _ac, g _bc, need to get rid of wherein two.Use two screening conditions below:

1, intersection point must, on the limit of Triangular object model, must not be (distance by decision-point and point realizes in program length) on extended line.

2, coordinate figure must increase in the axial direction, and namely the coordinate z value of yarn drop point must increase.

Can find out in the b of Fig. 6, only have g _bcmeet two conditions above.The Triangular object model information obtaining this drop point place is needed after finding next drop point, can find that in the c of Fig. 6 next Triangular object model must be adjacent with current bin, and adjacent bin necessarily meets the such condition of two common vertex, and next drop point one fixes on the line of two common vertex simultaneously.The above-mentioned algorithm of Reusability, from subpoint to line with line intersection point to adjacent surface, just can realize in a program, and obtain all yarn drop points, thus formation track.

Further, in above-mentioned algorithm, the given of time step will affect whole result, and time step can be obtained by formula below:

Wherein N _trepresent the number of triangles of yarn process required for the rectangular blocks, why introducing this variable is to solve situation as shown in Figure 7, under different coiling speeds, yarn differs widely through the number of triangles required for a rectangular blocks, this will cause a problem, because on guide ring, contact point is that each time step is through a point in the algorithm, and yarn under a time step through a triangle, according to actual conditions, on guide ring, contact point rotates 360 °, a circle, yarn must also make a circle, this is so just realistic.So as shown in Figure 7, when coiling speed is excessive, the number of triangles of the axially process of yarn in a rectangular blocks is too much, and does not rotate corresponding angle in a rotational direction, causes contact point and yarn drop point on guide ring to occur different phenomenon.Introduce a kind of algorithm of adaptive time-step below to contact this problem.

First given N _tan initial value 1, namely assert that yarn is 1 through the Triangular object model quantity required for a rectangular blocks, or takes 1 time step.Given N _tvalue after, the value of time step can be obtained according to formula (9).Above-mentioned algorithm is used to calculate yarn drop point, until the angle that yarn turns in a rotational direction reaches the border of this rectangular blocks.This judgement can be calculated by the distance between the subpoint of the end points in calculating yarn drop point and this rectangular blocks in xy plane in a program, if distance is 0, just illustrates and reaches border.Simultaneously really the Triangular object model number of process or time step long number are designated as N ' to yarn _t, this is behind the border in order to reach rectangular blocks, with N _tvalue compare, if unequal, given N is described _tinitial value incorrect, at this moment at N _tinitial value on add 1, recalculate the drop point of yarn in this rectangular blocks.Until N _twith N ' _tvalue equal till.If equal, carry out next rectangular blocks.Can ensure that the contact point on yarn drop point and guide ring is synchronous by such mode.

After yarn track is tried to achieve, braid angle, as an important parameter of yarn track, passes through two adjacent yarn impact point calculation braid angles as shown in Figure 8.Formula is as follows:

$\mathrm{\α}=\left|\arccos \frac{\stackrel{\→}{n_1}\·\stackrel{\→}{n_2}}{\left|\stackrel{\→}{n_1}\right|\·\left|\stackrel{\→}{n_2}\right|}\right|---\left(10\right)$

Wherein the vector of the line of two adjacent drop points, denotation coordination z-axis is projected in the vector on two adjacent drop point place Triangular object model.

Above embodiment is only the preferred embodiment of this creation, and not in order to limit this creation, any amendment made within all spirit in this creation and principle, equivalent replacement, improvement etc., within the protection domain that all should be included in this creation.

Claims (5)

1., based on a yarn track method for solving for the arbitrary section mandrel of annular weaving, it is characterized in that: circular knitting machine comprises spooler, mandrel, yarn, spindle, guide ring and big disk; Setting mandrel coiling speed is left set to alphabetical V, and spindle rotational angular velocity is set to ω _s, guide ring radius is R _g; The point that yarn contacts with guide ring is set to q, and the point that yarn contacts with mandrel is called drop point p, and yarn drop point is set to H to the distance of guide ring ₀, the contact point angular velocity of yarn on guide ring is also ω _s; It comprises the steps:

1), the surface segmentation by an arbitrary section mandrel: first in a rotational direction mandrel is divided into the dry rectangular blocks of promise, more axially according to certain axial step-length even partition, the diagonal line finally connecting each rectangle obtains minimum unit triangle gridding; Wherein each rectangular blocks occupies an angle ω in a rotational direction _s;

2), the initial drop point p of every one thread is set ₀with the initial contact point q on guide ring ₀;

3), preset time step delta t, according to angular velocity omega _scontact point q on next guide ring just can be obtained with coiling speed V ₁, and be q ₁at initial drop point p ₀subpoint q ' on the Triangular object model of place ₁, then connect subpoint q ' ₁with initial drop point p ₀can meet at a certain bar limit of this triangular facet thus obtain intersection point, this intersection point is exactly next drop point p ₁; Reusability said method obtains all drop points of yarn, thus forms a track;

4), after yarn track is tried to achieve, by two adjacent yarn impact point calculation braid angles, formula is as follows:

$\mathrm{\α}=\left|\arccos \frac{\stackrel{\→}{n_1}\·\stackrel{\→}{n_2}}{\left|\stackrel{\→}{n_1}\right|\·\left|\stackrel{\→}{n_2}\right|}\right|;$

Wherein the vector of the line of two adjacent drop points, denotation coordination z-axis is projected in the vector on two adjacent drop point place Triangular object model.

2., as claimed in claim 1 based on the yarn track method for solving of the arbitrary section mandrel of annular weaving, it is characterized in that: described spooler pulls mandrel toward left movement; Two groups of spindles do clockwise and counterclockwise movement around big disk center respectively, so yarn also does clockwise and counterclockwise movement.

3., as claimed in claim 1 based on the yarn track method for solving of the arbitrary section mandrel of annular weaving, it is characterized in that: described step 2) concrete grammar as follows: the initial angle of given n-th one thread meet following condition: find this rectangular blocks position, yarn initial point place; Wherein, angle with two end points according to leg-of-mutton wherein two summit projection formation rectangular blocks any in rectangular blocks obtain; Then from true origin along angle the line doing two end points of straight line and rectangular blocks produces an intersection point, and this intersection point is exactly the initial drop point p of this yarn ₀;

Other yarn uses formula:

Obtain initial angle, and initial drop point p can be obtained ₀;

Be uniformly distributed on 360 °, a circle according to number of yarns, obtain all yarns equally distributed initial contact point q on guide ring ₀.

4., as claimed in claim 1 based on the yarn track method for solving of the arbitrary section mandrel of annular weaving, it is characterized in that: described step 3) in, time step Δ t adopts following methods to obtain: given N _tan initial value 1, namely assert yarn through the Triangular object model quantity required for a rectangular blocks be 1; Given N _tvalue after, according to formula

obtain the value of time step.

5. as claimed in claim 1 based on the yarn track method for solving of the arbitrary section mandrel of annular weaving, it is characterized in that: described step 3) in, whether yarn drop point site accurately adopts with the following method: by calculating the distance between the end points in yarn drop point and rectangular blocks, if distance is 0, just illustrates and reach border; Simultaneously the Triangular object model number of yarn process or time step long number are designated as N ' _t; N ' _twith N _tvalue compare, if unequal, given N is described _tinitial value incorrect, at this moment at N _tinitial value on add 1, recalculate the drop point of yarn in this rectangular blocks; Until N _twith N ' _tvalue equal till.