CN102674043A - Variable speed paper feed mechanism and fixed groove cam plate thereof - Google Patents

Abstract

The invention discloses a variable speed paper feed mechanism and a fixed groove cam plate thereof. The mechanism comprises a power input shaft, a planetary swing arm, a planetary gear swing arm, a first intermediate shaft, a cam roller, a first transmission gear, the fixed groove cam plate and a paper feed line tape roller, wherein the planetary swing arm is fixed on the power input shaft; the left end of the planetary swing arm is hinged with the planetary gear swing arm; the right end of the planetary gear swing arm is meshed with the first transmission gear fixed on the first intermediate shaft; the left end of the planetary gear swing arm and the cam roller are meshed in a cam groove of the fixed groove cam plate; and the first intermediate shaft is fixed on the fixed groove cam plate and drives the paper feed line tape roller to rotate. The mechanism can achieve that the paper has constant speed operation sections in the period of motion so as to improve the paper skip stability during joint of a paper receiving roller and a paper transferring suction nozzle mechanism while achieving the aim of variable speed paper feed and has simple mechanical structure.

Description

A kind of speed change paper feed mechanism and hold down groove lobe plate thereof

Technical field

The present invention relates to print field, be meant a kind of speed change paper feed mechanism and hold down groove lobe plate thereof especially.

Background technology

Along with improving constantly of the speed of sheet-fed press, the delivery speed of the paper of paper feeding machine on defeated cardboard platform also improves constantly.It is accurate that every paper all must accurately be located to guarantee chromatography by preceding rule and side mark before getting into printing element, and the front edge of sheets edge needs on the go directly to lean against on the static preceding predetermined bits plate the circumferential location with the completion printed sheet.Therefore, when the delivery speed of paper is too high, occur faults such as curl in the trimming, paper resilience when very easily causing paper to contact the location with preceding predetermined bits plate, what influence was printed normally carries out.In order to address this problem; The modern high speed sheet-fed press generally adopts the speed change paper feed mechanism; Make in the time of each cycle of operations, still the pass by distance of a defeated paper step pitch of paper, promptly average velociity is constant, but the running velocity in this cycle is non-constant.Like this; Paper runs at high speed away from preceding predetermined bits plate the time, and changes low cruise into during the predetermined bits plate before being about to run into, because the average velociity in the whole cycle is constant; Make paper feed speed can meet the requirement of high speed printing, can prevent that again paper from breaking down when the location.At present, the speed change paper feed mechanism of Modern High-Speed printer employing mainly comprises: rotating guide-bar speed change paper feed mechanism, non-circular gear speed change paper feed mechanism, gear connecting rod combination speed change paper feed mechanism and cam link gear combination speed change paper feed mechanism.

In recent years, again traditional non-circular gear speed change paper feed mechanism was improved, designed the vibration when overcoming its high-speed operation of two kinds of dampings and compensation mechanism, improved the stability of defeated paper.As shown in Figure 1, be that gear connecting rod speed change paper feed mechanism is analyzed and studied, the motion analysis model that has provided based on matrix method, and combine defeated paper technology to set up speed change paper feed mechanism design optimization design mock-up and and calculated examples.

Although several kinds of speed change paper feed mechanisms that the front is introduced all have practical application and some structural improvement in recent years, they still have not enough place.Thereby the speed change paper feed mechanism must be furnished with compensation mechanism and carry out vibration damping and cause mechanism's more complicated, and it is stable that the speed change paper feed mechanism can not realize that all paper has the paper feed of constant speed target phase when improving the splicing roller with the handing-over of transfer suction nozzle body in orbit period.

Summary of the invention

In view of this; The objective of the invention is to propose a kind of speed change paper feed mechanism and hold down groove lobe plate thereof; It is stable that the purpose that can realize the defeated paper of speed change can realize that paper has the paper feed of constant speed target phase when improving the splicing roller with the handing-over of transfer suction nozzle body simultaneously in orbit period, and physical construction is simple.

Based on above-mentioned purpose speed change paper feed mechanism provided by the invention, comprise power input shaft, planet swing arm, planetary wheel swing arm, first tween drive shaft, cam roller, first transmission gear, hold down groove lobe plate and defeated paper yarn band roller;

Power input shaft is fixed in described planet swing arm, and the left part of described planet swing arm and said planetary wheel swing arm are hinged; Described planetary wheel swing arm right-hand member is through meshing with said first transmission gear that is fixed on described first tween drive shaft, and described planetary wheel swing arm left end and described cam roller are engaged in the cam path of described hold down groove lobe plate; Said first tween drive shaft is fixed in described hold down groove lobe plate, and said first tween drive shaft drives described defeated paper yarn band roller and rotates.

Optional, described planet swing arm left part joins through bearing pin and said planetary wheel swing arm.

Optional, described planetary wheel swing arm left end is engaged in the cam path of described hold down groove lobe plate through bearing pin and described cam roller.

Optional, described hold down groove lobe plate is fixed in wallboard through double end stud.

Optional, described power input shaft is axially fixed at wallboard.

Optional, described defeated paper yarn band roll shaft is to being fixed in wallboard.

Optional, said speed change paper feed mechanism comprises second tween drive shaft, and said first tween drive shaft links to each other with the engagement of said second tween drive shaft through two transmission gears, and said second tween drive shaft links to each other with the engagement of said defeated paper yarn band roller through two transmission gears simultaneously.

Optional, described second tween drive shaft is axially fixed on the described hold down groove lobe plate.

Optional, the described second tween drive shaft bottom is axially fixed at wallboard.

Optional, described planet swing arm comprises the clump weight that is processed as one with the planet swing arm.

Based on above-mentioned purpose; The present invention also provides the hold down groove lobe plate based on the speed change paper feed mechanism, comprises hold down groove, and the cam profile of said hold down groove is based on above-mentioned speed change paper feed mechanism; Speed change according to first transmission gear is rotated curve, adopts the method based on conjugate curved surface principle to obtain.

Optional, it is to have adopted B-spline curves to obtain that the speed change of described first transmission gear is rotated curve.

Optional, the actual internal profile of the cam profile of said hold down groove does

$\left\{\begin{array}{c}{x}_2=R_f\cos (u+{\mathrm{\&beta;}}_1+\mathrm{\&theta;})-L_r\sin ({\mathrm{\&beta;}}_1+\mathrm{\&theta;})+a\cos \mathrm{\&theta;}\\ {\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="DEST\_PATH\_HDA00001853032400021.png,HDA00001667581800011.png"\; state="\{\{state\}\}">y</figure-callout>}}_2=R_f\sin (u+{\mathrm{\&beta;}}_1+\mathrm{\&theta;})+L_r\cos ({\mathrm{\&beta;}}_1+\mathrm{\&theta;})+a\sin \mathrm{\&theta;}\end{array}\right.$

Wherein, R _fBe roller radius of cam mechanism, β ₁Be the angular transposition of planetary wheel swing arm, L _rBe the length of planetary cam swing arm, a is the length of planet swing arm, the angle that θ rotates for the planet swing arm;

wherein, η is the angle that planetary wheel turns over around its center.

Optional, the actual profile of the cam profile of said hold down groove is to be 2R with actual internal profile distance _fEquidistant curve.

Saidly can find out that from top a kind of speed change paper feed mechanism provided by the invention and hold down groove lobe plate thereof adopt the planetary wheel mechanism of cam-controlled to realize that the periodicity speed change of defeated paper yarn band roller rotates, thereby realize the purpose of the defeated paper of speed change.Profile through rational design cam can make paper keep uniform movement at one-period in some period in the time under the prerequisite of the speed changing function of realizing the speed change paper feed mechanism, thereby improves the stability of opening the paper handing-over.

Description of drawings

Fig. 1 is prior art gear connecting rod combination speed change paper feed mechanism motion analysis model scheme drawing;

Fig. 2 is an embodiment of the invention speed change paper feed mechanism assembling scheme drawing;

Fig. 3 is an embodiment of the invention speed change paper feed mechanism variable-speed motion principle schematic;

Fig. 4 is that embodiment of the invention speed change paper feed mechanism variable-speed motion is analyzed scheme drawing;

Fig. 5 is the hold down groove cam profile method of designing schematic flow sheet of the embodiment of the invention based on the speed change paper feed mechanism;

Fig. 6 is that the speed change of the embodiment of the invention first transmission gear is rotated curve synoptic diagram;

Fig. 7 is the speed law curve synoptic diagram of embodiment of the invention cam follower;

Fig. 8 is the displacement curve scheme drawing of embodiment of the invention cam follower;

Fig. 9 is the angular transposition curve synoptic diagram of the embodiment of the invention first transmission gear;

Figure 10 is the transformation mechanism scheme drawing of the embodiment of the invention based on the reversal process principle;

Figure 11 is the profilograph scheme drawing of the hold down groove cam of embodiment of the invention speed change paper guide;

Figure 12 is the two dimensional motion emulation grabgraf of embodiment of the invention speed change paper feed mechanism.

The specific embodiment

For making the object of the invention, technical scheme and advantage clearer, below in conjunction with specific embodiment, and with reference to accompanying drawing, to further explain of the present invention.

Consult shown in Figure 2; Be embodiment of the invention speed change paper feed mechanism assembling scheme drawing, described speed change paper feed mechanism comprises power input shaft 1, planet swing arm 4, planetary wheel swing arm 6, first tween drive shaft 10, cam roller 7, first transmission gear 9, hold down groove lobe plate 13 and defeated paper yarn band roller 26.

In the embodiment of the invention, power input shaft 1 is fixed in described planet swing arm 4, and the left part of described planet swing arm 4 and said planetary wheel swing arm 6 are hinged; Described planetary wheel swing arm 6 right-hand members are through meshing with said first transmission gear 9 that is fixed on described first tween drive shaft 10, and described planetary wheel swing arm 6 left ends and described cam roller 7 are engaged in the cam path of described hold down groove lobe plate 13; Described first tween drive shaft 10 is fixed on the described hold down groove lobe plate 13, and said first tween drive shaft 10 drives described defeated paper yarn band roller 26 and rotates.

Described speed change paper feed mechanism also comprises big bearing pin 5 and small clevis pin with head; The left part of described planet swing arm 4 joins with said planetary wheel swing arm 6 through big bearing pin 5, and described planetary wheel swing arm 6 left ends are engaged in the cam path of described hold down groove lobe plate 13 through small clevis pin with head and described cam roller 7.

Described speed change paper feed mechanism is when work, and planet swing arm 4 is along with power input shaft 1 uniform rotation together, and then drive planetary wheel swing arm 6 swings; Because described planetary wheel swing arm 6 left ends are engaged in the cam path of described hold down groove lobe plate 13 through small clevis pin with head and described cam roller 7; So planetary wheel swing arm 6 has also received the control of hold down groove lobe plate 13, finally drive first tween drive shaft, 10 speed changes and rotate through described planetary wheel swing arm 6 right-hand member ingears first transmission gear 9; Said first tween drive shaft 10 drives defeated paper yarn band roller 26 speed changes and rotates.

Wherein, Described first tween drive shaft 10 is axially fixed on the described hold down groove lobe plate 13; The mounting means that adopts is: on the described hold down groove lobe plate 13 processing porose, there are two identical antifriction-bearing boxs 18 its inside, and two identical roller bearing end caps 17 are arranged at top; Lean on the shaft shoulder location on first tween drive shaft 10 below the described antifriction-bearing box 18, then withstand above the described antifriction-bearing box 18 by roller bearing end cap 17; Described two identical roller bearing end caps 17 are respectively arranged with attaching screw 16, and attaching screw 16 embeds described hold down groove lobe plate 13.Preferable, between described first tween drive shaft 10 and the said hold down groove lobe plate 13 that fixes axle sleeve 2 is housed, mainly be in order to reduce the loss of member.

Preferable; Described speed change paper feed mechanism comprises that the first connection double end stud 8 is connected double end stud 21 with second, and described hold down groove lobe plate 13 is connected double end stud 21 through the first connection double end stud 8 that is separately positioned on its right and left with second and is fixed on the wallboard 22.

Wherein, through antifriction-bearing box, roller bearing end cap and attaching screw described power input shaft 1 is axially fixed on the wallboard 22.Described defeated paper yarn band roller 26 utilizes roller bearing end cap 23, attaching screw 24 and antifriction-bearing box 25 to be axially fixed on the wallboard 22.

Also it is to be noted; Described speed change paper feed mechanism also comprises second tween drive shaft 15; Described second tween drive shaft 15 is provided with the 3rd transmission gear 14, and described the 3rd transmission gear 14 is meshed with second transmission gear 12 on being arranged on said first tween drive shaft 10.Described second tween drive shaft 15 adopts and is axially fixed on the described hold down groove lobe plate 13 with said first tween drive shaft, 10 the same seating meanses.

Described second tween drive shaft 15 also is provided with the 4th transmission gear 19, and described the 4th transmission gear 19 is meshed with the 5th transmission gear 20, and described the 5th transmission gear 20 is installed on the described defeated paper yarn band roller 26.Preferable, second tween drive shaft, 15 bottoms are axially fixed on the wallboard 22.

This shows that the engagement of described first tween drive shaft 10 through second transmission gear 12, the 3rd transmission gear 14 drives described second tween drive shaft, 15 speed changes and rotate; Then, the engagement through the 4th transmission gear 19, the 5th transmission gear 20 makes described defeated paper yarn band roller 26 do speed change and rotates output again.

It should be noted that planet swing arm 4 has been considered when its structure design requirement for dynamic balance is provided with clump weight; Described clump weight can be fixed in the planet swing arm 4 separately; The structure that also can be processed as one with planet swing arm 4, in the present embodiment, employing be the latter.

Consult shown in Figure 3; Be embodiment of the invention speed change paper feed mechanism variable-speed motion principle schematic; Wherein planet swing arm 4 is the driving link among Fig. 3; If its input angular velocity is ω, because the combined action of planetary wheel swing arm 6, cam roller 7 and hold down groove lobe plate 13 will make first transmission gear 9 do periodically speed change rotation, establishing first transmission gear, 9 output angle speed is ω _sHas identical diameter with defeated paper yarn band roller 26 and first transmission gear, 9 coaxial sprocket wheels respectively; Connect through chain simultaneously; When described first transmission gear, 9 speed changes are rotated; To make defeated paper yarn band roller 26 also do speed change and rotate, thereby make paper when carrying, have periodically variable paper feed speed, use V _fExpression.

It should be noted that in Fig. 3 to drive through chain-driving that defeated paper yarn band roller 26 speed changes rotate, in the present embodiment, preferably adopt gear transmission.Use gear transmission can improve the stationarity of transmission, be suitable for the demand of high-speed motion.

Consult shown in Figure 4ly, be that embodiment of the invention speed change paper feed mechanism variable-speed motion analyzes scheme drawing, wherein O _s, O _p, O _fBe respectively the center of first transmission gear 9, planetary wheel and cam roller 7; Z _sAnd Z _pBe respectively first transmission gear 9 and the planetary number of teeth, modulus is m; First transmission gear 9 is planet swing arm 4 with planetary centre distance, and its length is a=0.5 (Z _s+ Z _p); The centre distance of planetary wheel and cam roller 7 is planetary cam swing arm 6, and its length is L _r

If first transmission gear, 9 center O _sWith cam roller 7 center O _fBetween line of centers be r, then according to the cosine law, must have:

${\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="DEST\_PATH\_HDA00001853032400021.png,HDA00001667581800011.png"\; state="\{\{state\}\}">r</figure-callout>}}^2=a^2+L_r^2-{2\mathrm{aL}}_r\cos \mathrm{\&delta;}---\left(1\right)$

Wherein, δ-line of centers O _fO _pWith line of centers O _sO _pBetween angle.

Obviously, in whole rotation period, the length of r is constantly to change, and the length of planet swing arm 4 and planetary cam swing arm 6 remains unchanged.For guaranteeing the certainty of mechanism kinematic, must guarantee L _r+ a>R set up in whole turning interval.

Can find out that thus when being located at initial position E, first transmission gear 9 is positioned on the X axle with planetary point of engagement P, then cam roller 7 will forward the F position to after planet swing arm 4 conter clockwises turn over the θ angle.Consider that it is linear moving between each member in the mechanism, can motion of mechanism be decomposed, and suppose that they are motions successively according to the motion principle of superposition.The concrete narration as follows: at first; Suppose that first transmission gear 9 all is fixed in the planet swing arm 4 with planetary wheel; And remove stationary cam temporarily and impose on planetary constraint, then work as planet swing arm 4 and turn over after the θ angle, first transmission gear 9 also can forward F ' position to it with planetary wheel.Secondly, it is fixed in current location to establish planet swing arm 4, and first transmission gear 9 all can freely rotate around center separately with planetary wheel, and the effect of contraction owing to 13 pairs of planetary cam swing arms 6 of hold down groove lobe plate can force planetary wheel around its present center O _pTurn over angle η (during the cw swing is negative value), thereby make cam roller move to its actual position F by position F '.Simultaneously, because the engagement of the planetary wheel and first transmission gear 9 will make first transmission gear 9 around its center O _sTurn over angle ξ, and naming a person for a particular job on first transmission gear 9 that coincides with P in the E position and the planetary wheel forwards P respectively to _sAnd P _p

Can know that according to fwd analysis and narration after planet swing arm 4 turned over the θ angle, first transmission gear 9 was respectively with planetary actual displacement:

θ _p＝θ+η （2）

θ _s=θ+ξ

θ wherein _P-planetary angular transposition;

θ _sThe angular transposition of-the first transmission gear 9;

According to the drive connection of external meshing tooth, must have

$\mathrm{\&xi;}=-\frac{z_p}{z_s}\mathrm{\&eta;}---\left(3\right)$

With also arrangement in formula (3) the substitution formula (2), can get

${\mathrm{\&theta;}}_s=\mathrm{\&theta;}-\frac{z_p}{z_s}\mathrm{\&eta;}---\left(4\right)$

With formula (4) respectively to the time ask once, second derivative coefficient can get

${\mathrm{\&omega;}}_s=\mathrm{\&omega;}(1-\frac{z_p}{z_s}\&CenterDot;\frac{\mathrm{d\&eta;}}{\mathrm{d\&theta;}})$

（5）

${\mathrm{\&epsiv;}}_s=-{\mathrm{\&omega;}}^2\frac{z_p}{z_s}\&CenterDot;\frac{{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="DEST\_PATH\_HDA00001853032400021.png,HDA00001667581800011.png"\; state="\{\{state\}\}">d</figure-callout>}}^2\mathrm{\&eta;}}{{\mathrm{d\&theta;}}^2}$

ω in the formula _sThe cireular frequency of-the first transmission gear 9;

ε _sThe angular acceleration of-the first transmission gear 9;

The cireular frequency of ω-planet swing arm 4;

Obviously, can know that angle η is by the profilograph decision of the hold down groove lobe plate 13 in the mechanism by above-mentioned analysis.Therefore, the profile that designs different cams as required can be controlled the output movement of first transmission gear 9.

Particularly importantly; The present invention proposes a kind of hold down groove lobe plate based on above-mentioned speed change paper feed mechanism; As shown in Figure 2; Described hold down groove lobe plate 13 comprises hold down groove, and the cam profile of said hold down groove is to rotate curve according to the speed change of first transmission gear 9, adopts the method based on conjugate curved surface principle to obtain.

Consult shown in Figure 5ly, be the hold down groove cam profile method of designing schematic flow sheet of the embodiment of the invention, comprising based on the speed change paper feed mechanism:

Step 501 is done periodically speed change rotation according to speed change paper feed mechanism of the present invention, calculates the speed change of described first transmission gear and rotates curve, and concrete implementation procedure is following:

1) embodiment of the invention speed change paper feed mechanism is done periodically speed change rotation; See also shown in Figure 6; For the speed change of the embodiment of the invention first transmission gear is rotated curve synoptic diagram: what transverse axis was represented is the corner of cam driving link, and what the longitudinal axis was represented is the cireular frequency of first transmission gear 9.

According to formula (5), because in a rotation period, hold down groove lobe plate 13 will be controlled planetary wheel and make reciprocally swinging.Therefore, the mean angular velocity of first transmission gear 9 in one-period is:

${\stackrel{\&OverBar;}{\mathrm{\&omega;}}}_5=\mathrm{\&omega;}$

Hence one can see that, paper in the time in each cycle, will travel forward identical distance, i.e. a defeated paper step pitch.And the paper feed speed of any time of paper in the cycle is:

$V_f=\frac{s_0}{1000T}\frac{{\mathrm{\&omega;}}_5}{{\mathrm{\&omega;}}_1}---\left(6\right)$

Wherein, s ₀The defeated paper step pitch of-paper feeding machine;

The print cycle of T-printer.

Can know through above-mentioned analysis, as if the Changing Pattern V that has confirmed the variable-speed motion that conveyance of sheets is required according to printing process conditions _f(θ), can release the characteristics of motion of first transmission gear 9.Instance below in conjunction with concrete describes.

The print out rate of supposing certain sheet-fed offset press is 18000/hour, and promptly the cireular frequency of driving link planet swing arm 4 is ω=10 π rad/s, and the print cycle is T=0.2s.If the defeated paper step pitch of its paper guide is 205mm; Then defeated paper average velociity is that

is for easy design; Specific adopted moderating ratio τ, then the maxim of the cireular frequency of first transmission gear 9 and minimum value can be expressed as:

ω _5max＝ω(1+τ)

ω _5max＝ω(1-τ) （7）

The value of moderating ratio τ depends on concrete technological condition, general desirable 15%～30%.The value of reduction of speed coefficient is unsuitable excessive, otherwise will make the highest paper feed speed value excessive and the phenomenon of paper feed shakiness occurs.In this example, get τ=0.2, then can know that by formula (7) and formula (6) extreme value of the cireular frequency of first transmission gear 9 and the extreme value of paper feed speed are respectively

ω _5max=12π?rad/s,V _fmax=1.23m/s

（8）

ω _5min=8π?rad/s,V _fmin=0.82m/s

In order to guarantee the stability of defeated paper and paper handing-over, be located in the whole orbit period, paper promptly has two identical constant speed target phases of time span with keeping the highest paper feed speed and minimum identical time period of paper feed speed motion respectively.Through rational layout, make paper and preceding predetermined bits plate be in minimum running velocity when colliding, and in high-speed constant speed section, accomplish the handing-over of splicing roller and transfer suction nozzle, improve the stability of defeated paper.

According to the cireular frequency curve of needed first transmission gear 9 of the technological requirement jointing positions of known conditions and numerical value speed change, promptly the speed change of first transmission gear is rotated curve, and each section arranged as follows:

First section, θ is from 0 ° to 160 °, and the cireular frequency of first transmission gear 9 is from ω _5minChange to maxim ω _5max, and when θ=80 °, ω _s=ω=10 π rad/s;

Second section, θ is from 160 ° to 180 °, and first transmission gear 9 keeps ω _5maxThe speed constant speed rotate;

The 3rd section, θ is from 180 ° to 340 °, and the cireular frequency of first transmission gear 9 is from ω _5maxBe reduced to minimum value ω _5min, and when θ=260 °, ω _s=ω=10 π rad/s;

The 4th section, θ is from 340 ° to 360 °, and first transmission gear 9 keeps ω _5minThe speed constant speed rotate.

Wherein, first section cireular frequency curve adopts B-spline curves, can provide following boundary condition according to known conditions

During θ=0 °, ω ₅=ω _5min, ε=0, jerk=0;

During θ=80 °, ω ₅=10 π rad/s;

During θ=160 °, ω ₅=ω _5max, ε=0, jerk=0;

Have 7 boundary conditions, the exponent number of getting the B batten is k=5, and then the analogy B-spline curves are found the solution the step of cam curve, and correlation parameter can be taken as:

tau=[0,0,0,80,160,160,160]

m=[0,1,2,0,0,1,2]

(9)

T=[0,40,120,160]

F=[ω _5min,0,0,10π,ω _5max,0,0]

In the formula, the cooresponding angle position of tau-boundary condition;

The type of the kinematic constraint of the position of all angles described in m-tau, 0 expression displacement constraint, 1 expression constraint of velocity, 2 expression acceleration/accel constraints, 3 expression jerk constraints;

The sequence node of T-B-spline curves, wherein first point respectively repeats k time with the end point, is k=5 time in this example;

F-cooresponding the binding occurrence of each boundary constraint.

Second section and the 4th section is that simple constant speed is rotated segment of curve, need not design.The 3rd section curve still adopts the B batten, and according to known conditions, its boundary condition does

During θ=180 °, ω ₅=ω _5max, ε=0, jerk=0;

During θ=260 °, ω ₅=10 π rad/s;

During θ=340 °, ω ₅=ω _5min, ε=0, jerk=0;

The exponent number of still getting B-spline curves is k=5, and then the relative parameters setting of the 3rd section B-spline curves does

tau=[180,180,180,260,340,340,340]

m=[0,1,2,0,0,1,2] （10）

T=[180,220,300,340]

F=[ω _5max,0,0,10π,ω _5min,0,0]

Call the automatic calculation program according to the parameter setting in formula (9), the formula (10) and obtain each section curve respectively, after splicing, can obtain ω ₅Diagram of curves, promptly the speed change of first transmission gear 9 is rotated curve.

It should be noted that the design of follow-up for ease cam profile, the position that diagram of curves shown in Figure 6 makes θ=260 in the former splicing diagram of curves ° obtains as the starting point of motion.

Step 502 is rotated the velocity variations law curve that curve draws cam follower according to the speed change of first transmission gear

The speed law curve of cam follower obtains the displacement curve η of cam follower to the θ integration; The speed change of first transmission gear is rotated curve to time t integration, obtains the rotational angle theta of first transmission gear 9 in the mechanism ₅Variation rule curve; The practical implementation process is following:

1) rotates curve according to the speed change of first transmission gear 9; Calculate the Changing Pattern of

; Be the follower motion of cam: the speed change of first transmission gear 9 that from step 501, obtains is rotated curve; According to formula (5), can calculate the Changing Pattern of

.Promptly can obtain the speed law curve of cam follower, see also shown in Figure 7ly, be the speed law curve synoptic diagram of embodiment of the invention cam follower.Wherein, what transverse axis was represented is the angle that the cam driving link rotates, and what the longitudinal axis was represented is the speed of cam follower.

2) the speed law curve of cam follower obtains the angular transposition of cam roller to the θ integration, i.e. the variation rule curve of η sees also shown in Figure 8ly, is the displacement curve scheme drawing of embodiment of the invention cam follower.Wherein, the angle that transverse axis rotates for the cam driving link, the longitudinal axis is that planetary wheel is around its present center O _pThe angle η that turns over.

3) speed change of first transmission gear is rotated curve to time t integration, can obtain the rotational angle theta of first transmission gear 9 in the mechanism ₅Variation rule curve, see also shown in Figure 9ly, be the angular transposition curve synoptic diagram of the embodiment of the invention first transmission gear.

Step 503; Variation rule curve according to η and

also adopts the method for calculating based on conjugate curved surface principle; Try to achieve the profilograph of the hold down groove cam that satisfies speed change request, the practical implementation process is following:

1) according to the variation rule curve of η and

and adopt method of calculating based on conjugate curved surface principle, can be in the hope of the profilograph of the hold down groove cam that satisfies speed change request.

In the present embodiment, in order to design the stationary cam in this mechanism, adopt the reversal process principle, promptly suppose to apply a public-ω, then obtain shown in figure 10ly, be the transformation mechanism scheme drawing of the embodiment of the invention based on the reversal process principle to entire mechanism.In this transformation mechanism, planet swing arm 4 becomes fixed, thereby cam will clockwise rotate with the cireular frequency of ω and promote planetary wheel swing arm 6 and rotate in fixed axis around its center, and 9 of the protoplanet gear and first transmission gears constitute a common fixed shaft gear train.Cam profile design in this transformation mechanism adopts the design formula based on Theory of Conjugate Surface to calculate.

At first set up system of axes shown in Figure 10, wherein fixed coordinate system σ and the moving coordinate system σ that is connected with cam ₂Initial point O and O ₂Center O with first transmission gear 9 _sOverlap the moving coordinate system σ that is connected with planetary wheel swing arm 6 ₁Initial point then with planetary center O _pOverlap.

Cam angle θ in the transformation mechanism ₂, planetary wheel swing arm 6 angular displacement beta ₁Have following corresponding relation with the related angle in the former mechanism shown in Fig. 4:

θ ₂=-θ

β ₁=-(β ₁₀+η)

In the following formula, the initial pivot angle of planetary wheel swing arm 6 can be tried to achieve by following formula

${\mathrm{\&beta;}}_{10}={\mathrm{\&delta;}}_0-\frac{\mathrm{\&pi;}}{2}$

If the base radius on the cam profile of cam is R _b, roller radius of cam mechanism is R _f, then can know initial position angle δ by formula (1) ₀Can try to achieve by following formula

${\mathrm{\&delta;}}_0=\arccos \left(\frac{a^2+L_r^2-{(R_b+R_f)}^2}{{2\mathrm{aL}}_r}\right)$

The actual internal profile equation that in view of the above, can get cam does

$\left\{\begin{array}{c}{x}_2=R_f\cos (u+{\mathrm{\&beta;}}_1+\mathrm{\&theta;})-L_r\sin ({\mathrm{\&beta;}}_1+\mathrm{\&theta;})+a\cos \mathrm{\&theta;}\\ {\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="DEST\_PATH\_HDA00001853032400021.png,HDA00001667581800011.png"\; state="\{\{state\}\}">y</figure-callout>}}_2=R_f\sin (u+{\mathrm{\&beta;}}_1+\mathrm{\&theta;})+L_r\cos ({\mathrm{\&beta;}}_1+\mathrm{\&theta;})+a\sin \mathrm{\&theta;}\end{array}\right.---\left(11\right)$

Wherein, $u=\mathrm{Arctg}\left(\frac{a\mathrm{Sin}{\mathrm{\&beta;}}_1-L_r(1+\frac{\mathrm{D\&eta;}}{\mathrm{D\&theta;}})}{-a\mathrm{Cos}{\mathrm{\&beta;}}_1}\right).$

In like manner, the angle of obliquity that can know this cam mechanism does

α=180-|u|

In formula (11), make R _f=0 can obtain the pitch curve equation of cam.The method for solving that this grooved cam is positioned at the cam profile equation in the pitch curve outside is discussed below.Because being distances, the profile of cam and its internal profile be 2R _fEquidistant curve, therefore, can complete class than the method for solving of cam internal profile equation.Promptly at first at driven member moving coordinate system σ ₁Try to achieve with the cam profile on the roller that overlaps of point on the coordinate expression formula of point, adopt the means of homogeneous coordinate transformation that it is transformed into cam system of axes σ then ₂Can obtain the cam profile equation asked.Shown in Fig. 6-8, suppose at system of axes σ ₁In, with the coordinate of point on the roller that the actual profile of cam contacts for (x ' ₁, y ' ₁), then must have

$\left\{\begin{array}{c}{x}_1^{\&prime;}=x_1+{2R}_f\cos \mathrm{\&alpha;}\\ {\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="DEST\_PATH\_HDA00001853032400062.png,HDA00001667581800011.png"\; state="\{\{state\}\}">y</figure-callout>}}_1^{\&prime;}={\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="DEST\_PATH\_HDA00001853032400062.png,HDA00001667581800011.png"\; state="\{\{state\}\}">y</figure-callout>}}_1+{2R}_f\sin \mathrm{\&alpha;}\end{array}\right.$

Following formula can be put in order and do

$\left\{\begin{array}{c}{x}_1^{\&prime;}=R_f\cos u+2R_f\cos \mathrm{\&alpha;}\\ {\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="DEST\_PATH\_HDA00001853032400062.png,HDA00001667581800011.png"\; state="\{\{state\}\}">y</figure-callout>}}_1^{\&prime;}=(L_r+R_f\sin u)+{2R}_f\sin \mathrm{\&alpha;}\end{array}\right.$

Principle according to homogeneous coordinate transformation is transformed into cam system of axes σ with this point ₂In and arrangement, can obtain the actual profile equation of cam

$\left\{\begin{array}{c}{x}_2^{\&prime;}=x_1^{\&prime;}\cos ({\mathrm{\&beta;}}_1+\mathrm{\&theta;})-{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="DEST\_PATH\_HDA00001853032400062.png,HDA00001667581800011.png"\; state="\{\{state\}\}">y</figure-callout>}}_1^{\&prime;}\sin ({\mathrm{\&beta;}}_1+\mathrm{\&theta;})+a\cos \mathrm{\&theta;}\\ {\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="DEST\_PATH\_HDA00001853032400021.png,HDA00001667581800011.png"\; state="\{\{state\}\}">y</figure-callout>}}_2^{\&prime;}=x_1^{\&prime;}\sin ({\mathrm{\&beta;}}_1+\mathrm{\&theta;})+{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="DEST\_PATH\_HDA00001853032400062.png,HDA00001667581800011.png"\; state="\{\{state\}\}">y</figure-callout>}}_1^{\&prime;}\cos ({\mathrm{\&beta;}}_1+\mathrm{\&theta;})+a\sin \mathrm{\&theta;}\end{array}\right.$

Obviously, method recited above can be used for finding the solution arbitrarily and the curvilinear equation of the actual internal profile equidistance of cam.

In the present embodiment, the number of teeth of getting the planetary wheel and first transmission gear is respectively 20 and 40, and the modulus of the number of teeth is got m=2, and the length of planetary wheel swing arm 6 is L _r=35mm, the radius of cam roller are R _f=10mm, the base radius value of actual internal profile is R _b=60mm.Automatic calculating and emulation program according to above known conditions establishment are tried to achieve the cam contour line chart; Figure 11 is the profilograph scheme drawing of the hold down groove cam of embodiment of the invention speed change paper guide, and Figure 12 is the two dimensional motion emulation grabgraf of embodiment of the invention speed change paper feed mechanism.

A kind of speed change paper feed mechanism and hold down groove lobe plate thereof that the present invention proposes; The creationary periodicity speed change of the defeated paper yarn band roller of planetary wheel mechanism realization of cam-controlled that adopted is rotated; Thereby realized the purpose of the defeated paper of speed change; Profile through rational design cam can make paper keep uniform movement at one-period in some period in the time under the prerequisite of the speed changing function of realizing the speed change paper feed mechanism, thereby improves the stability of opening the paper handing-over.

The those of ordinary skill in affiliated field is to be understood that: the above is merely specific embodiment of the present invention; Be not limited to the present invention; All within spirit of the present invention and principle, any modification of being made, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (14)

1. a speed change paper feed mechanism is characterized in that, comprises power input shaft, planet swing arm, planetary wheel swing arm, first tween drive shaft, cam roller, first transmission gear, hold down groove lobe plate and defeated paper yarn band roller;

Power input shaft is fixed in described planet swing arm, and the left part of described planet swing arm and said planetary wheel swing arm are hinged; Described planetary wheel swing arm right-hand member is through meshing with said first transmission gear that is fixed on first tween drive shaft, and described planetary wheel swing arm left end and described cam roller are engaged in the cam path of described hold down groove lobe plate; Said first tween drive shaft is fixed in described hold down groove lobe plate, and said first tween drive shaft drives described defeated paper yarn band roller and rotates.

2. mechanism according to claim 1 is characterized in that, described planet swing arm left part joins through bearing pin and said planetary wheel swing arm.

3. mechanism according to claim 2 is characterized in that, described planetary wheel swing arm left end is engaged in the cam path of described hold down groove lobe plate through bearing pin and described cam roller.

4. mechanism according to claim 1 is characterized in that, described hold down groove lobe plate is fixed in wallboard through double end stud.

5. mechanism according to claim 4 is characterized in that described power input shaft is axially fixed at wallboard.

6. mechanism according to claim 4 is characterized in that, described defeated paper yarn band roll shaft is to being fixed in wallboard.

7. mechanism according to claim 1; It is characterized in that; Said speed change paper feed mechanism comprises second tween drive shaft; Said first tween drive shaft links to each other with the engagement of said second tween drive shaft through two transmission gears, and said second tween drive shaft links to each other with the engagement of said defeated paper yarn band roller through two transmission gears simultaneously.

8. mechanism according to claim 7 is characterized in that, described second tween drive shaft is axially fixed on the described hold down groove lobe plate.

9. mechanism according to claim 8 is characterized in that, the described second tween drive shaft bottom is axially fixed at wallboard.

10. according to any described mechanism of claim 1 to 9, it is characterized in that described planet swing arm comprises the clump weight that is processed as one with the planet swing arm.

11. hold down groove lobe plate based on the speed change paper feed mechanism; It is characterized in that; This hold down groove lobe plate is based on any described speed change paper feed mechanism of claim 1-10; Said hold down groove lobe plate comprises hold down groove, and the cam profile of said hold down groove is to rotate curve according to the speed change of first transmission gear, adopts the method based on conjugate curved surface principle to obtain.

12. hold down groove lobe plate according to claim 11 is characterized in that, it is to have adopted B-spline curves to obtain that the speed change of described first transmission gear is rotated curve.

13. hold down groove lobe plate according to claim 12 is characterized in that, the actual internal profile of the cam profile of said hold down groove does

$\left\{\begin{array}{c}{x}_2=R_f\cos (u+{\mathrm{\&beta;}}_1+\mathrm{\&theta;})-L_r\sin ({\mathrm{\&beta;}}_1+\mathrm{\&theta;})+a\cos \mathrm{\&theta;}\\ y_2=R_f\sin (u+{\mathrm{\&beta;}}_1+\mathrm{\&theta;})+L_r\cos ({\mathrm{\&beta;}}_1+\mathrm{\&theta;})+a\sin \mathrm{\&theta;}\end{array}\right.$

Wherein, R _fBe roller radius of cam mechanism, β ₁Be the angular transposition of planetary wheel swing arm, L _rBe the length of planetary cam swing arm, a is the length of planet swing arm, the angle that θ rotates for the planet swing arm;

$u=\mathrm{Arctg}\left(\frac{a\mathrm{Sin}{\mathrm{\&beta;}}_1-L_r(1+\frac{\mathrm{D\&eta;}}{\mathrm{D\&theta;}})}{-a\mathrm{Cos}{\mathrm{\&beta;}}_1}\right)$ Wherein, η is the angle that planetary wheel turns over around its center.

14. hold down groove lobe plate according to claim 13 is characterized in that, the actual profile of the cam profile of said hold down groove is to be 2R with actual internal profile distance _fEquidistant curve.

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