CN1100031A - Fast brake method and rotary key clutch brake mechanism for press - Google Patents

Abstract

A technical specification for safe braking and relative mathematical formula are created according to travelling distance, frequency and bench size of press and man-machine relationship. Through analysis for medium-size and small presses, only rotary key clutch with quick brake mechanism may be used to implement safe braking, that is, emergency braking angle must be smaller than safe stop angle and convenient angle and the key-releasing angle must be as small as possible. Its embodiment and calculation formula are designed.

Description

Fast brake method and rotary key clutch brake mechanism for press

The invention belongs to middle-size and small-size safe pressure machine fast braking method and rotating key clutch arrestment mechanism.

Can realize stopping in emergency in order to make positive clutch; condition is provided for the safe manoeuvring of forcing press; domestic multiple rotating key clutch with anxious stop mechanism appearred; stepless tiny motion rigid clutch punch press as the production of forging press factory, Cangzhou, Hebei; the QF-1 type punch press of Shanghai Lighter Factory series safety device for emergency braking, the inventor is the disclosed stepless brake device that is made of block key pin and belt brake disc etc. in No. 86104198 patent applications once.But through nearly ten years facts have proved, though these schemes plausible in theory because in theory all or technologic problem is inconsiderate, or lacks necessary supporting technology, is all applied so far as yet.

At present, the definition and the technical indicator of secure mechanical forcing press or overload-release clutch still there are not unified saying and standard both at home and abroad, as the standard JB3350-83 of the machine Ministry of worker " mechanical pressure mechanism of qi safety specification " the 6th, article 12, the forcing press that will have two or more safety devices is called the safe pressure machine, but total brake hard response time is not proposed specific targets, just require the operator that safe distance is set in accordance with regulations." crank press " (He Deyu of Tsing-Hua University chief editor, China Machine Press, 1987 the 93rd page go up will " positive clutch with anxious stop mechanism be called safe positive clutch, or the title tiny motion rigid clutch ".This article has only been enumerated the technical parameter that certain scheme reached, and does not see demonstration but whether this parameter has satisfied safety requirements.ZB _nJ62016-88 " gap-framepress performance requirement and test method " has stipulated the drag angle index of friction clutch forcing press, does not also have test stone but whether this index satisfies the safety requirements of concrete lathe.What Japan plastic working association compiled " does not have this type of argumentation in the content of the 1043rd～1064 page of relevant safety device of pressure processing handbook (China Machine Press, in October, 1984 Chinese edition) yet.

The objective of the invention is to avoid above-mentioned the deficiencies in the prior art part, having designed a kind of brake hard angle need and make things convenient for the safe pressure machine fast braking method at angle and take off the rotating key clutch arrestment mechanism that bond angle is tried one's best little less than the safety angular stop.

Purpose of the present invention is to reach by following measure:

A kind of safe pressure machine fast braking method and rotating key clutch arrestment mechanism is characterized in that the brake hard angle α of forcing press in the safe pressure machine fast braking method _ZMethod for designing be: according to ram travel H, up and down die face join the height h _j, minimum safe height h _aCalculate safe angular stop α _A, with safe angular stop α _ADeduct not shielding angle α _PDifference as brake hard angle α _ZOne of maximum permissible value, according to width M before and after the platen, slide block continuous operation frequency n and the hand maximum movement speed V that makes things convenient for coefficient N and set in the world _HandCalculate and make things convenient for angle α ₁As brake hard angle α ₂Another maximum permissible value, with (α _A-α _P) and α ₁Minimum of a value as α _ZDesign objective, wherein, h _j=0.4H, h _a=20～35mm, α _p=10 °～60 °, N=3～4, V _Hand=1600mm/ second; Realize brake hard angle α _ZThe method of design objective is: use the response time less than the photoelectric sensor of 1.5ms, the response time braking drive organ less than the logic judgement of 0.5ms and power amplifier, pickup time 8～15ms, to brake time is controlled between 10～22ms, then according to the brake hard angle α of slide block continuous operation frequency n and setting _ZIndex calculates takes off bond angle α _{Take off}Design objective.

The present invention will be described in detail below in conjunction with accompanying drawing.

Fig. 1 is the operating mode simplified schematic diagram of existing crank press.

Fig. 2 is existing a kind of separate type safety positive clutch figure.

Fig. 3 takes off key arrestment mechanism schematic diagram for belt of the present invention.

Fig. 4 takes off key arrestment mechanism installation site schematic diagram on lathe for belt of the present invention.

Fig. 5 takes off key mode safety rotating key clutch structural representation for crank block of the present invention.

Fig. 6 takes off key mode safety rotating key clutch motion schematic diagram for crank block of the present invention.

Fig. 7 takes off key mode safety rotating key clutch structural representation for crank chute of the present invention.

Fig. 8 takes off key mode safety rotating key clutch motion schematic diagram for crank chute of the present invention.

At first analyze the actual brake hard angle index that the safe pressure machine should reach in conjunction with Fig. 1.

Among Fig. 1, H is a ram travel; The slide block lower edge of the h correspondence that is bent axle when top dead-centre begins to rotate the α angle is to the bottom dead centre height; h _jThe height of joining of die face up and down during to bottom dead centre for slide block movement; h _aThe crowded hand minimum safe height that die face should keep about when being defined as the slide block brake hard generally should be got 20～30 millimeters; h _ABe h ₁With h _aSum is defined as slide block safety shutheight herein; α _ABe and h _AThe angle that corresponding bent axle turns over from top dead-centre is defined as safe angular stop herein; L is a length of connecting rod.

According to the movement relation of slider-crank mechanism, can draw α and h has following relational expression:

$a={\cos }^{-1}\frac{1}{\mathrm{\λ}}[1-\sqrt{{(1+\mathrm{\λ})}^2-\frac{4\mathrm{\λh}}{H}}]---\left(1\right)$

In the formula, α, h, the meaning of H as previously mentioned, λ is the connecting rod coefficient, λ=(H)/(2L)

Use h _A=h _j+ h _aReplace the h of (1) formula, then obtain α _A:

$a_A={\cos }^{-1}\frac{1}{\mathrm{\λ}}[1-\sqrt{{(1+\mathrm{\λ})}^2-\frac{4\mathrm{\λ}(h_j+h_a)}{H}}]---\left(2\right)$

For the forcing press of general applications, mould join the height h _jFrom zero (during stamping-out) when 0.4H(extends) all possible, if all suitable to all situations, h _jShould obtain maximum 0.4H.h _aChoose, the size of rule of thumb visual machine tool travel H is determined: as H during less than 50 millimeters, h _aGet 20 millimeters, as H during greater than 100 millimeters, h _aGet 30 millimeters, when H is 50～100 millimeters, h _aGet 25 millimeters.

The maneuverability pattern of forcing press generally all has single stroke, continuous operation and three kinds of modes of self-act travel; the action of removing waste material and part in two kinds of row kind of the control modes of back and sending virgin material to all needs to finish to the stage that just begins to descend at the slide block uphill process; at this moment should allow the shading light curtain and not brake hard, the unprotected field function that promptly should possess the 6.4th, 7.4 defined of GB5091-85 " security device technology of forcing press requires " during this period of time just may be carried out the operation of continuous operation.This just requires both to have made hand shading light curtain, also wants bent axle to move to D point shown in Figure 1 and just begins to take place brake hard afterwards, so just draws first technical indicator of safe pressure machine brake hard performance:

The brake hard angle α of forcing press _Z(be defined as from hand and enter the angle that photoelectric sensor light curtain is turned over to the complete stopping period bent axle of slide block) should meet (3) formula and require:

α _Z≤α _A-α _p（3）

α _PBe defined as not shielding angle, can be generally between 10 °～60 ° according to the stroke and the continuous operation frequency selection purposes of lathe.

After the concrete data computation of substitution as can be known, be considered to state-of-the-art in the world friction clutch at present, (stroke H is less than 80 millimeters at the ordinary press below 25 tons, the number of strokes is greater than 100 min) on, its brake hard performance all can not satisfy the requirement of (3) formula, is then differing farther on the type lathe fast.

For the big lower lathe of stroke frequency of stroke, the brake hard angle satisfies (3) formula might not just can guarantee safety.Now continue to carry out analytical calculation with Fig. 1:

The moment that brake hard takes place in the slide block running makes slide block be parked in h _AWhen height is following, at h _aBe before zero, between the die face, still can hinder hand about being introduced into as if hand, this moment should be with light curtain safe distance D is set _sWay guarantee safety: when hand passes before the light curtain arrives die orifice, slide block is stop motion.This requires available (4) formula to represent:

(α _Z)/(ω)＞(D _S)/(V _Hand) (4)

In the formula, ω-angular velocity of crankshaft,

D _s-safe distance,

V _HandThe movement velocity of-hand generally is taken as 1600 mm/second.

Be that example is calculated with 63 tons of forcing presses now: 63 tons of forcing press parameters of standard type are:

The H=120 millimeter

λ=0.1

N=50 time/minute (number of strokes)

Width M=480mm before and after the workbench

Then have according to (2), (3), the calculating of (4) formula:

Get α _P=30 ° then

α _Z=75°-30°=45°

ω=6n=300（0/s）

D _s＞ (α _Z)/(ω) ×1600=240（mm）

Result of calculation shows that light curtain position must be arranged on outside the workbench and could guarantee safety.But in the practical operation, the operator feels inconvenience deeply for this reason, and for pursuing high workload efficient and often reducing labor intensity the light curtain near the mould setting, this just still might hinder the hand accident.Practice shows, only emphasizes that it is impracticable that the operator removes the excessive safe distance of strict execution, and radical solving method should be to go to design the brake hard angle according to the safe distance that the operator can accept.The inventor thinks safe distance is set at 1/4～1/3 of workbench front and back width that the operator still is willing to accept through investigating for many years.For this reason, the notion of one " making things convenient for the angle " is set: be handled easily according to the requirement of (4) formula, safe distance should not surpass 1/4～1/3 of workbench front and back width, should be in this interior chirokinesthetic time of distance greater than the required time of slide block brake hard, at this moment between the corner of inside crankshaft be called and make things convenient for the angle.

Make things convenient for the angle to calculate with (5) formula:

α _f= (3M·n)/(800N) （5）

In the formula, α ₁-side establishes the angle, degree,

Width before and after the M-workbench, mm,

N-continuous operation frequency, inferior/min,

N-makes things convenient for coefficient, when M≤300

Get N=3, when M＞3000, get N=4.

Like this, just draw second technical indicator of safe pressure machine brake hard performance:

α _Z＜α _f（6）

Comprehensively (3), (6) two formula requirements, for a concrete lathe, its minimum of a value should be got in actual brake hard angle, and available (7) formula is represented:

(7) formula is exactly the primary index of the safe pressure machine that proposes of the present invention brake hard performance that should reach, go to verify domestic various clutches or stepless tiny motion rigid clutch as can be known with this index, have only indivedual special cases of only a few to reach reluctantly, but do not have versatility.The friction clutch that developed country more generally adopts does not then all reach this index on middle-size and small-size forcing press.(referring to " crank press " the 114th page of " actual drag angle " formula)

Be the actual brake hard angle index that realizes that (7) formula proposes, the design that the present invention takes is as follows:

At first, the overall process with brake hard is decomposed into six time phases:

1, photo-sensor signal will T conversion time ₁

2, logic judgement time T ₂

3, power amplifier T time delay ₃

4, driving mechanism run duration T ₄

5, take off key process time T ₅

6, inertia braking time T ₆

Then actual brake hard time T should meet (8) formula and require:

$T=\underset{i=1}{\overset{6}{\mathrm{\Σ}}}{T}_i\≤\frac{{\mathrm{az}}_{\max }}{6n}---\left(8\right)$

In the formula, α Z _MaxThe result that (7) formula of serving as reasons calculates, n is the stroke frequency, unit is inferior/min.

For these six periods, traditional design is all undesirable.The present invention has designed special parts and circuit respectively at the specific (special) requirements of each link: " safe pressure machine photoelectric sensor " can be with T ₁Be controlled at below the 1.5ms; " Safty rigid clutch press control device " can be with (T ₂+ T ₃) be controlled at below the 0.5ms; " safe pressure machine braking drive organ " can be with T ₄Be controlled at 8～15ms, its power output can be with T ₆Be controlled at 1～5ms.(T then ₁+ T ₂+ T ₃+ T ₄+ T ₆)=T ' (be called and brake time) can be controlled between 10～22ms.Can calculate thus and take off the key time T ₅:

${\mathrm{<figure-callout\; id="5"\; label="T"\; filenames="931117356\_DRIMG2.png"\; state="\{\{state\}\}">T</figure-callout>}}_5\&le;\frac{{\mathrm{az}}_{\max }}{6n}-T^{\&prime;}---\left(9\right)$

Then take off the leading indicator-Tuo bond angle α of key mechanism _{Take off}(throwing off the angle that bent axle turns over fully to clutch from beginning to take off key) can be calculated by (10) formula:

α _{Take off}≤ dz _Max-6nT ' (10)

Take off bond angle according to what (10) formula was determined, the bond angle that promptly takes off of medium-sized rotating key clutch forcing press generally all need be below 20 °, and is that have even little to about 10 °, and the type forcing press is because stroke is little fast, the frequency height, and taking off bond angle also needs littler.The key mechanism of taking off of general design does not reach requirement.As No. 86104198 patent applications described take off key mechanism take off bond angle in 20 °～30 ° scopes, but the superiority of its belt arrestment mechanism and braking force adjustment device is obviously easily seen: brake disc inertia is little, easy to loading and unloading, make simple, can be applicable in transformation with lathe, also can be used for the design of new machine, braking moment is reliable and stable.Only need calculate and to reach requirement of the present invention the further well designed of the binding site of its brake disc and key tail.

Also have in the existing mechanism a kind of can be near the bond angle index of taking off of the present invention, i.e. the above separate type safety positive clutch of the 93rd～94 page of preamble " crank press " mentioned.Fig. 2 is its sketch.Operation principle is: stop collar 2 is affixed with bent axle 1 usefulness flat key, and its cylindrical matches with gear wheel 3.The inner ring of gear wheel processes cam curve.Cam curve engagement on the key tail of this cam curve and turn key 8.When the anxious stopping time of needs forcing press, brake 4 brakings, pinion is motionless, and then gear wheel is fixed.Bent axle is rotated further (being illustrated as counter-clockwise direction).Because relative motion, turn key goes to imaginary line position, clutch separation.At this moment, the limit piece that puts in being contained in 7 bumps against with the groove of gear wheel, and and status of a sovereign brake (the original brake of forcing press) absorb the unnecessary kinetic energy of servo system together, forcing press is stopped in emergency.Desire need rerun, and can be releasing of brake, gear wheel resets to counter-clockwise direction under the effect of back-moving spring 10, simultaneously turn key be in conjunction with the original spring of spring 6() effect under reset, clutch is combination again.When operate as normal, above-mentioned anxious stop mechanism is inoperative, and turn key is by in conjunction with spring 6 and the original closer of closer 9() acting in conjunction be issued to the start-stop purpose.

This scheme is compared with No. 86104198 described schemes of patent application, and its advantage is to adopt the cam-type turn key to quicken releasing mechanism, and turn key breaks away from rapidly.But its shortcoming is apparent equally: 1, Design of cam curves processing difficulties; 2, big pinion is compared the cost height with band brake, inertia is big, and the difficulty that resets is installed trouble, and noise is big; 3, be not easy to reequip existing lathe.4, fault rate is big, if limited block 7 or back-moving spring 10 damage, the indefinite or irreducible fault in the cam curve position of engagement will take place.

Fig. 3, Fig. 4 take off key arrestment mechanism schematic diagram for the belt that the present invention adopts, its driving mechanism, lever system, brake band, brake disc, dial parts such as key pin and No. 86104198 patent applications basic identical, operation principle is also similar substantially to the separate type safety positive clutch in " crank press ".Characteristics of the present invention be dial keyway 12 and dial the shape of key pin 13 and the installation site through special design, can resemble cam and quicken to take off the quick key that takes off the key mechanism, can design processing easily by the utmost point again.

Fig. 5 is one of the key scheme key that takes off of the present invention, dials keyway 12 processing on brake disc 11, and columniform group of key pin 13 is installed on the former key tail.Be characterized in dialling keyway 12 to crankshaft rotating direction and angle beta of brake disc radial skew ₁, β ₁The summit be positioned at as crankshaft center O ₁, turn key pivot O ₂, dial the key pin center O ₈O when being positioned on the straight line ₈The place, this moment, turn key and interior cover were in complete engagement.

Motion schematic diagram when Fig. 6 takes off key for Fig. 5 mechanism now illustrates O in conjunction with Fig. 6 ₃Point and β ₁Design and calculation method.

Figure 6 shows that the slider-crank mechanism of a band eccentric throw: O ₁O ₂(O ₁O ₂') be crank, its length R is determined by former Machine Tool design, O ₂' O ₃' position when just having separated for turn key is because of dialling key pin 13 on the key tail, so length of connecting rod L and O ₂O ₃Equate α ₀The turn key of determining for former design separates the angle of rotation that needs, and is generally 45 ° or 30 °; R is for dialling the maximum radius size (comprising presumable movable pad) of key pin 13, and D is the internal diameter of brake disc 11.α _{Take off}The desired value that is exactly the design is taken off bond angle.δ is the maximum pressure angle of slide block in this mechanism (dialling key pin 13), should verify whether self-locking to take place.

Design calculation formula is as follows:

$l\&GreaterEqual;\sqrt{{(\frac{1}{2}D+r+C)}^2-{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="931117356\_DRIMG2.png"\; state="\{\{state\}\}">R</figure-callout>}}^2\sin a_0}-R\cos a_0---\left(11\right)$

δ=α _o-α _{Take off}+ β ₁≤ 55 ° (13)

α _{Take off}≤ α _Zmax-6nT ' (10)

(11) C in the formula takes off the minimum clearance value that key failure fault is provided with, general desirable 3～5mm for avoiding because of mismachining tolerance causes mechanical stuck generation.

This scheme generally is used for the repacking of existing lathe, because of only need one of processing being installed by the circular hole of dialling key pin 13 on original key tail, in the anti-position that connects the car projection of original installation brake disc being installed former clutch is not had other change.Generally speaking, this scheme all can satisfy the requirement of (10) formula, and shortcoming is α _{Take off}Can not do forr a short time (is α in theory _{Take off}It is better little to heal), reason is the restriction that the l size is subjected to original mechanical dimension, difficult minimum of a value setting of calculating by (11) formula, β ₁Be subjected to the restriction of (13) formula δ≤50, also can not obtain too big, so " cam acceleration " effect less.

Fig. 7 is two of the key scheme of taking off of the present invention, dials keyway 12 processing on the key tail, and columniform group of key pin 13 is installed on the brake disc 11.Be characterized in dialling the center line of keyway 12 and turn key key tail along β of crankshaft rotating direction inclination ₂Angle, β ₂The summit be positioned at key tail center line O ₂A and the intersection point O that dials keyway 12 center lines ₃On, O ₄For being fixed on the center of dialling key pin 13 on the brake disc 11, when turn key during in the position of engagement fully, O ₃, O ₄Overlap all the other symbol R, α _o, r, l, D meaning with scheme one.

Motion schematic diagram when Fig. 8 takes off key for Fig. 7 mechanism, can derive following design calculation formula according to this figure:

1≥ 1/2 D+r+C-R（14）

β ₂≤55°（16）

α _{Take off}≤ α _Zmax-6nT ' (10)

Scheme two can be used for manufacturing and designing of new machine, and advantage is that the l value can design lessly, β ₂The β of the comparable scheme one of angle value ₁About being twice, and dialling keyway 12 and be located on the key tail with high mechanical properties, needn't add guide rail, compact dimensions.

β ₁, β ₂Value should grasp flexibly, as long as can satisfy (10) formula requirement, can get forr a short time as far as possible, even desirable negative value so that pressure angle reduces, helps motion of mechanism.

It is pointed out that the α that basis (12) formula or (15) formula calculate _{Take off}Value is theoretic numerical value, if do not note the cooperation of other relevant size, actual α _ZValue might not guarantee to meet the requirement of (7) formula., have only when the groove of the limited block among Fig. 27 and brake disc bumps against effect is just arranged, for the inertia braking of taking off bent axle behind the key such as, this arrestment mechanism if the position of the two collision will increase the time T of inertia braking with respect to taking off key position at a distance of too big ₆, cause that actual drag angle increases.

Enforcement test according to several years, proof the design method is fully feasible, 6.3 tons～100 tons ordinary press with this programme repacking, can both reach (7) formula requirement, its safe distance has only 1/3～1/5 of friction clutch lathe, satisfied operator's requirement, for rakish forcing press, because of being used for the stamping-out operation, approach null value as long as the hj in (2) formula got more, then for stroke 20～30mm, frequency is up to the forcing press of 300 times/min, and this programme is also in full force and effect, and effect is better, total brake hard time of this moment can be below 30ms, and safe distance is less than the length of a finger.

Claims (2)

1, a kind of safe pressure machine fast braking method and rotating key clutch arrestment mechanism is characterized in that the brake hard angle α of safe pressure mechanism _zMethod for designing be: according to ram travel H, up and down die face join the height h _j, minimum safe height h _aCalculate safe angular stop α _A, with safe angular stop α _ADeduct not shielding angle α _pDifference as brake hard angle α _zOne of maximum permissible value, according to width M before and after the platen, slide block continuous operation frequency n and the hand maximum movement speed V that makes things convenient for coefficient N and set in the world _HandCalculate and make things convenient for angle α _lAs another maximum permissible value of brake hard, with (α _A-α _p) and α _lMinimum of a value as α _zDesign objective, wherein, h _j=0.4H, h _a=20～35mm, α _p=10 °～60 °, N=3～4, V _Hand=1600mm/ second; Realize brake hard angle α _zThe method of design objective is: use the response time less than the photoelectric sensor of 1.5ms, the response time braking drive organ less than the logic judgement of 0.5ms and power amplifier, pickup time 8～15ms, to brake time T ' and be controlled between 10～22ms, then according to the brake hard angle α of slide block continuous operation frequency n and setting _zIndex calculates takes off the design objective that bond angle α takes off.

2, safe pressure machine fast braking method and rotating key clutch arrestment mechanism is characterized in that in the rotating key clutch arrestment mechanism:

A, group keyway (12) processing are on brake disc (11), and columniform group of key pin (13) is installed on the former key tail, dials keyway (12) to crankshaft rotating direction and angle beta of brake disc radial skew ₁, β ₁The summit be positioned at as crankshaft center O ₁, turn key pivot O ₂, dial the key pin center O ₃O when being positioned on the straight line ₃The place;

B, group keyway (12) processing are on the key tail, and columniform group of key pin (13) is installed on the system dish (11), and the center line of dialling keyway (12) and turn key key tail is along β of crankshaft rotating direction inclination ₂Angle, β ₂The summit be positioned at key tail center line O ₂A and the intersection point O that dials keyway (12) center line ₃On, O ₄For being fixed on the center of dialling key pin (13) on the brake disc (11).

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