CN1079514C - Variable pitch high speed feeding screw and its manufacture - Google Patents

Abstract

The present invention relates to a variable pitch screw in a screw type high speed member division supply and delivery device, and a making method thereof. The present invention adopts the novel method that technological requirements for supply and delivery are analyzed; similar multisection functions are selected; the similar multisection functions are expanded and uniformed by series; the item number of the similar multisection functions is changed in order to change the waveforms of the similar multisection functions; the waveforms are preferably selected according to a precision requirement or other requirements. The motion law of a global united novel screw is further deduced. The present invention is particularly suitable for CAD/CAM, and a computer is used for analyzing and explaining characteristics. The present invention can favorably meet the technological requirements of high speed member division supply and delivery. The present invention relates to a global natural continuous superior motion law which has good water inertial impact and dynamic characteristics and convenient application.

Description

Variable pitch high speed feeding screw and manufacture method thereof

The present invention relates to varying pitch screw and manufacture method thereof in a kind of screw type high speed bulk-breaking feeder.

Screw type high speed bulk-breaking feeder is a base apparatus commonly used in the High-Speed Automatic packaging system.This device mainly is to lean on the wherein spiral chute deformation of varying pitch screw to control each motion, the kinetic parameter of feed object, to reach the purpose of high speed bulk-breaking feed.Therefore, the characteristics of motion of screw rod plays a part extremely crucial to the performance of device.But the varying pitch screw in the existing high speed bulk-breaking feeder, its characteristics of motion acceleration are multistage, and different functions are spliced, and its design is more numerous, segmentation to calculate match, and are not easy to computer-aided design and manufacturing (CAD/CAM).In addition, the object of feed can cause interference with follow-up bottle moving star-wheel, needs the excision thumb wheel, can reduce the stability of feed object thus.

Purpose of the present invention is exactly in order to address the above problem, and proposes a kind of simplicity of design, is convenient to computer design and manufacturing and do not have the variable pitch high speed feeding screw and the manufacture method thereof of interference phenomenon.

Technical solution of the present invention:

A kind of variable pitch high speed feeding screw, it includes varying pitch screw, it is characterized in that the pitch Changing Pattern of screw rod should satisfy following condition:

Wherein: p represents the pitch of screw rod,

represents the corner of screw rod,

_pExpression screw rod acceleration liter (falling) journey corner,

_mThe omnidistance total angle of rotation of expression screw rod,

ρ represents the radius of arc of screw spiral trough,

λ is _pWith _mRatio, that is: λ= _p/ _m

C _bDistance between the adjacent two allocating slot centers of the follow-up bottle moving star-wheel of expression screw rod also claims pitch.

A kind of manufacture method of variable pitch high speed feeding screw is characterized in that:

A, according to high speed bulk-breaking feed technological requirement:

Promptly at the import section, screw rod should be positive variable accelerated motion;

At main feed section, screw rod should be uniform accelerated motion;

In conversion section, screw rod should be negative variable accelerated motion;

And the linking of each section motion of screw rod must be continuous nothing sudden change; Obtain the piecewise function of screw motion acceleration:

Wherein f (x) represents the segmentation acceleration of screw rod,

A represents the accekeration of accelerating sections such as screw rod,

x _pThe lift interval of expression screw rod acceleration,

x _mTotal interval of expression screw rod acceleration;

B, above-mentioned piecewise function f (x) carried out digital processing and Computer Analysis obtain the omnidistance unified acceleration function of screw rod:

A () wherein---the omnidistance unified acceleration of expression screw rod

---screw rod corner

A---screw rod maximum acceleration value

_p---the interval corner of acceleration lift

_m---the omnidistance total angle of rotation of screw rod;

C, the whole process of screw rod unified acceleration function a () carry out the omnidistance unified displacement movement function s () of feed object central point that digital processing obtains screw rod:

D, with function s () programming back input numerical control milling machine, promptly available model becomes processing method to produce to meet the screw rod of claim 1 variable pitch requirement.

The present invention has done new analysis to the feed technological requirement of screw type high speed bulk-breaking feeder, and has found a kind of omnidistance feeding screw characteristics of motion unified, that be fit to CAD/CAM with new method on this basis.Analyzed each charcteristic function and the image thereof of new rule on computers, proved that it can satisfy the technological requirement of high speed bulk-breaking feed fully, be a kind of omnidistance naturally continuously, inertia impact is little, dynamic property good and the good easily characteristics of motion of application.The bulk-breaking feeder that adopts new rule screw rod has been carried out interference analysis, proved that it can not change again under the condition of system layout relation neither excising thumb wheel, object is had interferences, do not have with impacting and be not converted to thumb wheel by screw rod.The present invention manufactures and designs simply, is convenient to the computer design manufacturing, has very big social benefit and economic benefit.

Fig. 1 is the theory structure schematic representation of existing variable pitch high speed feeding device;

Fig. 2 is the theory structure schematic representation of variable pitch high speed feeding device of the present invention;

Fig. 3 is the primary election functional picture of the omnidistance acceleration change rule of screw rod of the present invention;

Fig. 4 is the image when the k value upper limit is tending towards ∞ in the primary election function;

Fig. 5 is the image when the k value upper limit is very little in the primary election function;

Fig. 6 is the functional picture of the omnidistance acceleration change rule of screw rod of the present invention;

Fig. 7 is a bulk-breaking feeder interference analysis sketch of the present invention;

Force analysis schematic representation when Fig. 8 is a feed cylindrical object of the present invention;

Fig. 9 is that screw rod of the present invention is at asynchronous acceleration of λ value and impact value image.

As Fig. 1, when typical screw type high speed bulk-breaking feeder was worked, object 1 moved right under the delivery of delivery board chain 2, after waveform buffer 3, lines up the single-row of end-to-end, enters screw rod bulk-breaking feeder.Under the control of varying pitch screw 4 spiral fluteds, object 1 is space out progressively, and change speed, acceleration reach and the synchronous conversion requirement of bottle moving star-wheel 5 thumb wheel groove O points at outlet O place.By bottle moving star-wheel 5 object 1 is sent into multiple package position along double-deck arc-shaped guide plate 6 then.The working condition of analyzing this device as can be known, its feature is " barrier type ", i.e. the power of object 1 motion comes from the frictional force of plate chain 2, screw rod 4 is not to push but the motion of " restriction " object 1 according to certain rules makes it reach required state.In order to carry out the bulk-breaking feed at a high speed, reposefully, different technological requirement (referring to Fig. 1) has been proposed for the different sections of screw rod 4:

At import section I, object 1 is imported smoothly, do not produce phenomenons such as lodging, jam.By the feature of installing as can be known, it is active force and frictional force maximum, the screw rod 4 also the most serious section that weares and teares between maximum, the object 1 of speed difference and the screw rod 4 between object 1 and the plate chain 2 herein, should reduce the waiting time of object 1 at this section as far as possible, and unlike " push-type " screw rod, a constant speed stabilization sub stage be arranged.Therefore, except adopting taper type screw rod profile, object can be imported outside the spiral chute smoothly, this section should adopt positive variable accelerated motion rule.So both can shorten the length of high speed difference section, can reduce resistance to motion and friction rapidly again, object 1 is separated as early as possible, prevent jam.But the variation of screw rod 4 acceleration must be risen gradually by zero, and sudden change must not be arranged, in case produce rigid impulse.

At main feed section II, should make the spacing of object 1 and speed reach the output requirement as early as possible.Simultaneously, to guarantee that also maximum acceleration is no more than allowable value, in case produce excessive inertial force, influences stationarity.Therefore, this section should adopt the uniform accelerated motion rule, and its advantage is that maximum acceleration is little, and time cross-section is big, but not only makes within a short period of time the object motion reach requirement, can also make acceleration and inertial force reduce to minimum.Simultaneously, can make screw rod 4 shorten lengths, help improving the rigidity and the intensity of screw rod, the volume of whole device also dwindles.

At conversion section III, object 1 must not produce with bottle moving star-wheel 5 interferes and impact.This turns over a groove except guaranteeing bottle moving star-wheel 5, outside the basic demand of an object 1 of screw rod 4 feeds, object 1 is moved all the time in the space that bottle moving star-wheel 5 thumb wheel grooves allow, and takes place to prevent to interfere.Because bottle moving star-wheel 5 is uniform rotation, the horizontal component of its centripetal acceleration reduces to zero at conversion section III gradually by sinusoidal rule, so screw rod 4 should be tried one's best near this variation in the characteristics of motion of this section, adopt negative the change to quicken rule, be beneficial to object 1 nothing and interfere, do not have the ground of impact smooth conversion.

At last, the whole characteristics of motion must be continuous, nothing sudden change at each section joining place, to guarantee the stationarity of screw rod 4 omnidistance feeds.

By above-mentioned technological requirement analysis as can be known, the acceleration change rule of screw rod 4 on its whole process should be zero → edge up → equivalent → edge up → zero ", the shape of this approximate trapezoid ripple (as shown in Figure 3), its function can be made as:

A in the formula---waveform peak

x _p---the lift interval

x _m---total interval

For making this piecewise function be converted into omnidistance mathematical model unified, that satisfy the feed technological requirement, the spy does following processing:

Earlier function is carried out strange continuation and periodic extension, uses the fourier series expansion again, obtain: $f\left(x\right)=\frac{4A{x}_m}{{\mathrm{\π}}^2{x}_p}\underset{k=1}{\overset{\∞}{\mathrm{\Σ}}}\frac{1}{{(2k-1)}^2}\sin \frac{(2k-1)\mathrm{\π}{x}_p}{x_m}\sin \frac{(2k-1)\mathrm{\π}}{x_m}x$

Obviously, this function is unified in total interval.But, by its image (as shown in Figure 4) as can be known, the situation of curvature mutation is arranged in the turning point of curve.As directly with it as acceleration diagram, then rigid impulse can appear owing to impact value is infinitely great.Therefore, must revise.Find when on microcomputer, the image of this function being analyzed: when the k value upper limit when diminishing greatly, functional picture fades to Fig. 5 from Fig. 4.Know by inference thus, wherein certainly exist some k value upper limit and can make waveform occur seamlessly transitting and satisfy the feed technological requirement.Now (get≤A%) the k value upper limit is carried out preferably in the fluctuation precision of intermediate space according to f (x).Consider the k value upper limit hour, curve turning point flatness is better, and then impact value is littler to make acceleration with it, is limited to 7 so get on the k value.For using conveniently, be independent variable directly with screw rod 4 corner , the omnidistance unified acceleration function of setting screw rod is:

in the formula---screw rod corner, rad, =ω t

ω---screw rod angular velocity, rad/s, ω=π n/30

N---screw speed, r/min

_p---the interval corner of acceleration lift, rad

_m---the omnidistance total angle of rotation of screw rod, rad

A---maximum acceleration value, m/s ²

Analyze image (as shown in Figure 6) as can be known by it, the Changing Pattern of a () meets the feed technological requirement fully, and transitions smooth, does not have sudden change, is a more satisfactory bulk-breaking feeding screw acceleration mathematical model.Its bulk-breaking feeder such as Fig. 2, it has reflected by the omnidistance acceleration movement rule of object 1 central point of screw rod 4 feeds (being the central point of screw spiral trough circular arc).This acceleration function a () is carried out twice integration can be obtained by the displacement function of object 1 central point of screw rod 4 feeds:

This formula both became to add the required function relation of following in man-hour for the numerical control model.Obviously, it is very easily for screw rod CAM.With function s () programming back input numerical control milling machine, can produce the screw rod 4 that meets pitch Changing Pattern ρ ().

Screw rod 4 with the said method manufacturing does not all have the sudden change generation at each interval joining place, all is continuous gradation in global extent.And, just at import section I and conversion section III, being subjected to certain soft impulse, and producing without any rigid impulse by the object 1 of screw rod 4 feeds, its dynamic property is reasonable, can guarantee object 1 steady feed.

As Fig. 7,, will interfere with bottle moving star-wheel 5 if object 1 has exceeded the space of bottle moving star-wheel 5 races at the movement position of conversion section III (among Fig. 7 on the bottle moving star-wheel scope shown in the dotted line).Usually prevent that the method for interfering from being with having the position of interference to cut with object 1 on the bottle moving star-wheel 5, as changing " C " shape groove into " L " shape groove (referring to Fig. 1).This method has no doubt been avoided interference, but has also reduced the reliability of system simultaneously.Another kind method is the configuration relation that changes bottle moving star-wheel 5 and screw rod 4.Make object 1 conversion avoid in advance constantly interfering.Because leading corner is wayward, all can bring difficulty for assembling, debugging and production.And adopt the feeder of screw rod of the present invention not change under the condition of system layout relation and avoid interfering neither excising thumb wheel.Now be analyzed as follows.

Get in the coordinate coefficient shown in Figure 7.R among the figure _bBe bottle moving star-wheel radius, O _bBe bottle moving star-wheel center of rotation, θ is a bottle moving star-wheel corner, and O ' is the center of circle of certain thumb wheel groove, O " be the object center of circle, r _wBe object or thumb wheel groove radius, object begins to be converted to bottle moving star-wheel at true origin O place from screw rod along x axle positive movement from-s ().The coordinate of moving some O ' is: x '=R _bSin θ y '=R _b(1-cos θ) bottle moving star-wheel notch A, 2 of B should satisfy set of equation: { x ²+ (y+R _b) ²=R _b ²(x-R _bSin θ) ²+ (y-R _b(1-cos θ)) ²=r _w ²Separate it:

ζ=r in the formula _w/ R _bChange a groove by bottle moving star-wheel 5, what screw rod 4 turned around is fixed than relation, as can be known: =Z _bθ is object 1 center O then " to true origin O apart from s _θFor: s _θ=s ( _m)-s ( _m-Z _bθ) And then try to achieve A, B at 2 to O " distance be respectively: $\stackrel{\&OverBar;}{{\mathrm{AO}}^{\&Prime;}}=\sqrt{{(X_A-s_{\mathrm{\&theta;}})}^2+{\mathrm{<figure-callout\; id="2"\; label="y\; A"\; filenames="C9811126200141.png"\; state="\{\{state\}\}">y</figure-callout>}}_A^{}}$ $\stackrel{\&OverBar;}{{\mathrm{BO}}^{\&Prime;}}=\sqrt{{(X_B-s_{\mathrm{\&theta;}})}^2+{\mathrm{<figure-callout\; id="2"\; label="y\; B"\; filenames="C9811126200141.png"\; state="\{\{state\}\}">y</figure-callout>}}_B^{}}$ Can establish the interference analysis function f thus _A(θ) and f _B(θ) be respectively: $f_A\left(\mathrm{\&theta;}\right)=\stackrel{\&OverBar;}{{\mathrm{AO}}^{\&Prime;}}-r_w=\sqrt{{(x_A-s_{\mathrm{\&theta;}})}^2+y_A^2}-r_w$ $f_B\left(\mathrm{\&theta;}\right)=\stackrel{\&OverBar;}{{\mathrm{BO}}^{\&Prime;}}-r_w=\sqrt{(x_B-s_{\mathrm{\&theta;}})+y_B^2}-r_w$

By COMPUTER CALCULATION as can be known, f _A(θ) and f _BMinimum (θ) is all more than or equal to zero.This proof can guarantee not change again under the condition of system layout relation neither excising thumb wheel with the new equipment of screw rod of the present invention, object is had with interfering be not converted to thumb wheel by screw rod.

Design from screw type bulk-breaking feeder, each parameter that generally is known feed object is (as boundary dimension, height of C.G., with friction factor of each associated components etc.), conditions such as feed ability that requires and bottle moving star-wheel pitch, then according to the characteristics of motion, feed stability, dynamic force balance and prevent that technological requirements such as jam from rationally determining the outer radius of screw rod, the spiral chute degree of depth, the screw rod active length, maximum feed acceleration, the maximum contact angle, intrinsic standoff ratio, parameters such as screw rod setting height(from bottom) and side board setting height(from bottom) are for the structural design of installing provides basic data.

The pitch p () that can be tried to achieve any place (before) by displacement function s () is: p ()=s ()-s (-2 π)

The pitch value p of ingress first lap ₁For:

In addition, for preventing that object 1 from inlet's extrusion and collision, should guarantee during design:

p ₁≥ω _x＋Δ _min

ω in the formula _x---object is at the overall dimensions of screw axis direction, mm

Δ _Min---the minimum clearance between the adjacent two articles, mm

The outer radius of determining screw rod is R: when the screw rod corner was , the circumferentially deploying length 1 of outer vortex was,

1=R or =1/R

Substitution s () is back to 1 differentiate, can get pitch angle alpha will and be:

When =0, α=α _Min=arctan (ρ/2 π R)

As = _mThe time, α=α _Max=arctan (C _b/ 2 π R)

The size of screw rod outer radius R and the force-bearing situation of object 1 have confidential relation.Force analysis sketch when Fig. 8 is screw type bulk-breaking feeder feed cylindrical object.Theoretically, object contacts along one section elliptic curve aob with spiral chute.To this " barrier type " feeder, because the existence in gap, the contacting point is at the b of the preceding bottom of object point but in fact.Again by object be cylindrical condition as can be known, b point place screw rod is to the positive pressure P of object _BnBe vertically to point to the object axis.If its azimythal angle (with the angle of x axle) is γ, can be with P _BnBe decomposed into P along right angled coordinates _BxAnd P _By, their ratio is called intrinsic standoff ratio:

ζ＝P _by/P _bx＝tanγ

Obviously, ζ is big more, side pressure P _ByJust big more, the resistance to motion of object is also just big more.For reducing side pressure, prevent jam, ζ should be controlled within the reasonable range.As can be seen from Figure 8; ${\{}_{y_b=r+r_w(1-\sin \mathrm{\&gamma;})}^{x_b=r_w\cos \mathrm{\&gamma;}}$

X in the formula _b---the x coordinate that b is ordered, mm

y _b---the y coordinate that b is ordered, mm

r _w---the radius of object main body, mm

R---screw rod inside radius, i.e. the radius of cylndrical surface, place at the bottom of the spiral chute, mm.General definite by structural strength.Special circumstances can strengthen, and need to guarantee feed.

In addition, according to object and screw rod pass through motion analysis mutually, have: ${\mathrm{<figure-callout\; id="2"\; label="y\; b"\; filenames="C9811126200141.png"\; state="\{\{state\}\}">y</figure-callout>}}_b^{}+\left(\frac{{\mathrm{<figure-callout\; id="2"\; label="P\; b"\; filenames="C9811126200141.png"\; state="\{\{state\}\}">P</figure-callout>}}_b}{2\mathrm{\&pi;}}\right)\frac{x_b^2}{r_w^2-{\mathrm{<figure-callout\; id="2"\; label="x\; b"\; filenames="C9811126200141.png"\; state="\{\{state\}\}">x</figure-callout>}}_b^{}}=R^2$ P in the formula _b---the pairing pitch of b point, mm

The outer radius of R---screw rod, mm can be got by following formula: $R=\sqrt{[r+r_w(1-\frac{\mathrm{\&epsiv;}}{\sqrt{1+{\mathrm{\&epsiv;}}^2}}){]}^2}+{\left(\frac{{\mathrm{<figure-callout\; id="2"\; label="P\; b"\; filenames="C9811126200141.png"\; state="\{\{state\}\}">P</figure-callout>}}_b}{2\mathrm{\&pi;\&epsiv;}}\right)}^2$

Obviously, R and pitch P _bBe directly proportional, be inversely proportional to ζ.Now with P _bWith its limiting value C _bReplace, and by side pressure relatively reasonably the situation scope of getting ζ be 0.5～1.0: $R_{\min }=\sqrt{{(r+0.3r_w)}^2+{\left(\frac{{\mathrm{<figure-callout\; id="2"\; label="C\; b"\; filenames="C9811126200141.png"\; state="\{\{state\}\}">C</figure-callout>}}_b}{2\mathrm{\&pi;}}\right)}^2}$ $R_{\max }=\sqrt{{(r+0.55r_w)}^2+{\left(\frac{C_b}{\mathrm{\&pi;}}\right)}^2}$

The span that can get R thus is:

R _min≤R≤R _max

For ease of making, R should guarantee that then ζ gets final product by the preferred value rounding within 0.5～1.0.Generally speaking, R more greatly, side pressure is just littler, object is difficult for jam.So under the situation that structure allows, R gets big value for well.

Determined after the R, can calculate spiral chute degree of depth h:

h＝R－r

Effectively the work calculating of total length H of screw rod, because new rule is omnidistance unified function, so H need not segmentation calculating, its total displacement promptly is the total length of effectively working.Obtain total angle of rotation earlier _m,

By following formula as seen, at known screw speed n, thumb wheel pitch C _b, object diameter ρ and corner become under the full condition than λ, can obtain as long as determined a _mFor this reason, press earlier following formula primary election a:

a＝(0.5～0.7) 〔a〕

In the formula (a)---maximum acceleration allowable during feed is proposed by technological requirement.Obtain _mAfter, should with its rounding the integral multiple of 2 π, inverse check a gets final product then.So far, with _mSubstitution displacement function s (), try to achieve the screw rod total length H that effectively works and be:

Or $H=\frac{C_b+\mathrm{\&rho;}}{2}{i}_m$

I in the formula _m---total work number of turns of screw rod.i _m＝ _m/2π

As seen, the calculating of H is very easy.This also is that new rule is convenient to one of advantages of application.

Secondly, deflect, should make the active force of its both sides not produce deflecting torque, promptly require b, c at 2 at sustained height for preventing object 1.Can get the configuration height h at side board center by Fig. 8 _cFor: $h_c=h_o-\sqrt{R-[r+r_w(1-\sin \mathrm{\&gamma;})]}$ Or $h_c=h_o-\sqrt{R-[r+r_w(1-\frac{\mathrm{\&epsiv;}}{\sqrt{1+{\mathrm{\&epsiv;}}^2}})]}$

h _oBe the screw axis configuration height.

Theoretically, guaranteeing that a is not more than under the condition of acceleration allowable (a) _mBe arbitrary value.But from practical application, _mShould be the integral multiple of 2 π, equate with the quantity that guarantees object 1 turnover screw rod 4.Work as _mAfter determining, _pJust answer choose reasonable.Because their ratio _p/ _mBe that corner becomes entirely than λ not simultaneously, acceleration diagram waveform difference, the impact value waveform is also different, and its situation of change is seen Fig. 9 (the λ span is 0.05～0.3).

As seen from the figure, the size of λ has determined the size in a () curve ascending, descending interval, has influence on the size of impact value peak value simultaneously.When λ≤0.1, the ascending, descending interval of a () curve is less, and beginning, the end of waveform are steeper, and the impact value peak value is bigger; Behind λ 〉=0.15, the ascending, descending of a () curve is interval to become big, and hold level with both hands smooth the whole story of waveform, and the impact value peak value reduces gradually.From improving the angle of screw rod dynamic property, λ gets bigger for well.But when λ was excessive, it is more that main feed section is dwindled, and a also rises to some extent, and this is undesirable.Therefore, the span of λ is advisable with 0.15～0.25.

In the process that screw type high speed bulk-breaking feeder is studied, the present invention adopts a kind of new method: analyze feed technological requirement → similar multistage function of selections → make function waveform variation → require preferred wave shape form according to precision or other with series expansion, unification → change function item number, and then released the omnidistance unified new screw characteristics of motion.The method constraint conditio is few, can be applied to analogue.

Each charcteristic function of the present invention is an independent variable with the screw rod corner directly all, and all is finite term summation form, is fit to very much CAD/CAM.With the specificity analysis explanation that computer carries out, it can satisfy high speed bulk-breaking feed technological requirement preferably, is that a kind of whole process is continuous naturally, inertia impact is little, dynamic property good and the good easily characteristics of motion of application.To the bigger parameter of the present invention influence is that corner becomes entirely than λ, its preferably span be 0.15～0.25.Work as C _b, λ one square being directly proportional of maximum acceleration a and rotation speed n regularly, with total angle of rotation _mBe inversely proportional to.

Interference analysis to apparatus of the present invention proves, new rule has fundamentally been eliminated the interference reason, can guarantee neither excising thumb wheel, do not change again to make object have impacts, not have with interfering and be not converted to thumb wheel by screw rod under the condition of system layout relation.This is the distinguishing feature that the present invention is better than other rule commonly used.

Claims (5)

1, a kind of variable pitch high speed feeding screw, it includes varying pitch screw, it is characterized in that the pitch Changing Pattern of screw rod should satisfy following condition: Wherein: p represents the pitch of screw rod,

represents the corner of screw rod,

_pExpression screw rod acceleration liter (falling) journey corner,

_mThe omnidistance total angle of rotation of expression screw rod,

ρ represents the radius of arc of screw spiral trough,

λ is _pWith _mRatio, that is: λ= _p/ _m

C _bDistance between the adjacent two allocating slot centers of the follow-up bottle moving star-wheel of expression screw rod also claims pitch.

2, variable pitch high speed feeding screw according to claim 1, it is characterized in that on the follow-up bottle moving star-wheel of screw rod each allocating slot shape can with matched by the sectional shape of feed object.

3, variable pitch high speed feeding screw according to claim 1 is characterized in that the outer radius R of screw rod should satisfy condition: $R=\sqrt{[r+r_w(1-\frac{\mathrm{\&epsiv;}}{\sqrt{1+{\mathrm{\&epsiv;}}^2}}){]}^2+{\left(\frac{P_b}{2\mathrm{\&pi;\&epsiv;}}\right)}^2}$

R in the formula _w---the radius of object main body

R---screw rod inside radius, the i.e. radius of cylndrical surface, place at the bottom of the spiral chute

P _b---the pairing pitch of b point.

4, variable pitch high speed feeding screw according to claim 1 is characterized in that the screw rod total length H that effectively works should satisfy condition:

Or $H=\frac{C_b+\mathrm{\&rho;}}{2}{i}_m$ I in the formula _m---total work number of turns of screw rod, i _m= _m/ 2 π.

5, a kind of manufacture method of variable pitch high speed feeding screw is characterized in that:

A, according to high speed bulk-breaking feed technological requirement:

Promptly at the import section, screw rod should be positive variable accelerated motion;

At main feed section, screw rod should be uniform accelerated motion;

In conversion section, screw rod should be negative variable accelerated motion;

And the linking of each section motion of screw rod must be continuous nothing sudden change; Obtain the piecewise function of screw motion acceleration:

Wherein f (x) represents the segmentation acceleration of screw rod,

A represents the accekeration of accelerating sections such as screw rod,

x _pThe lift interval of expression screw rod acceleration,

x _mTotal interval of expression screw rod acceleration;

B, above-mentioned piecewise function f (x) carried out digital processing and Computer Analysis obtain the omnidistance unified acceleration function of screw rod:

A () wherein---the omnidistance unified acceleration of expression screw rod

---screw rod corner

A---screw rod maximum acceleration value

_p---the interval corner of acceleration lift

_m---the omnidistance total angle of rotation of screw rod;

C, the whole process of screw rod unified acceleration function a () carry out the omnidistance unified displacement movement function s () of feed object central point that digital processing obtains screw rod:

D, with function s () programming back input numerical control milling machine, promptly available model becomes processing method to produce to meet the screw rod of claim 1 variable pitch requirement.

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