DE1752006B2 - Control for a shear line for trimming and dividing sheet metal, especially heavy sheet metal - Google Patents

Description

3. Control according to claim 2, characterized in that that the pulses for stopping SL B ^ feed by ^ comparison in The comparison device (60) emen the cutting stroke Part scissors (T) trigger automatically and the drive the sheet feed during the work cycle the dividing scissors electrically blocked, st.

15th

35 The invention relates to a control for a shear line for trimming and dividing metal sheets, in particular heavy plates, according to the preamble of claim 1. It is assumed that the shear line consists of long knife trimming shears with transverse knives for cutting off the edge strip and opposite each other on both sides of the roller table consists of a partial scissors arranged downstream at a short distance.

"The following problem arises when operating such a scissors unit: As long as the desired, The finished length WMi, which can be cut to length by the cut of the dividing scissors, is one or more times the normal fixed feed interval under which the sheet moves through the double trimming head If the amount deviates by a sufficiently large amount, the transverse knives cut the edge strip always in the full material. However, it cannot be ruled out that the desired finished length only is slightly greater than one or more times the fixed or set feed interval, so that there is a risk that the transverse knife is not far enough from the transverse knife sonitt edge of the start the penultimate cut away, slide off and forcefully move the sheet in the longitudinal direction, with which the given finished length is no longer correct. In such cases, the transverse knives could even no longer penetrate into the material, but it with a sudden increase in the horizontal component of the cutting pressure, which can break the cross knife assembly.

It is the object of the invention to provide the prerequisites for this by means of control measures to create that when a given finished length has been passed through the double trimming shears and the dividing shears have made the cut, the transverse knives of the continuously operated double trimming shears Always find a minimum length of the hem strips for cutting, at which a normal cut can be expected. This object is given by the characterizing part of claim 1 Features solved by using a forecast of the last to achieve the desired finished length required feed interval by comparison with a predetermined one Minimum feed interval, if necessary, the last feed interval at the expense of the penultimate one Feed interval is extended. If the double trimming shears then also with the last trimming 6s cut before switching on the partial scissors cuts "into the void", it is achieved that the cross knives always cut into solid.

The scissors control according to the invention is bottom knife 20 as well as two at a distance from each other

expediently in detail according to the features of the connecting rods 22, 24 articulated on the upper cutter 18

Claim 2 designed to recognize the driven by crank pins 26, 28

Because the control according to the invention - if they are ben. The parts labeled 18 and 20

if a given finished length equal to 5 is available, it can also be used as a knife carrier,

or only slightly larger than one or more times Fig. 3a is the starting position in which the

of the feed interval responds - leads to the settling of the crank drives being recognizable. ___

the sheet feed once more than is required. When the dividing shear is switched on, it

Lich takes place and by starting and braking the crank pins 26, 28 counterclockwise

If a certain amount of time is lost, it lies in the direction of the arrow according to the arrow direction.

men of the invention that the pulses to shutdown lines. In Fig. 3c, where the crank pin 26 about

of the sheet feed is in the bottom dead center position in the first due to zero comparison, the cut is halfway

Comparison device ended a cutting stroke of the dividing scissors.

trigger automatically and the drive of the sheet metal pre- To F i g. 3 d are both connecting rods 22, 24

Thrust during the working cycle of the dividing scissors! 5 ewa mirror image, and in Fig. 3e is the section

is electrically blocked. As a result, valuable time is completed, after which the crank pins 26, 28 in the

regained. Position according to FIG. 3 a are shut down.

The drawing shows an embodiment of the An advantageous mode of operation of the double-loading

Control of a shear line in connection with the trimming shear dividing shear unit according to the invention

Shear line short overall length after starting _ao dung is on hand of the circuit diagram according to F i g. 4th

Point of the invention shown, namely shows explained. Here, 32, 34 mean the power lines

F i g. 1 a side view of a Doppelbesäiim- an auxiliary control circuit, the line pair 36 the

scissors and a sub-network set up shortly behind it for operating the motors T of the sub-scissors and

scissors, the pair of lines 38 the network for operating the mo-

Fig. 2 a top view of the 25 toi en V of the feed means, ie the drive roller built scissors unit, pairs 4, 6, 8 and 10 and the driven roller

F i g. 3 an electrical circuit diagram for random rolling 2.

Kürliche and controlled shutdown of the drive rollers It has already been stated that the feed or. Feeding means, medium derived from the trimming

4 and 4b two representations of a sheet metal ₃₀ shear D ₁ and D., are switched on intermittently,

with the understanding of the invention for this purpose, a trimming on a crankshaft is used

Control for setting the desired sheet metal snips attached control cam disk 40, which is shown in

length required information and the indicated direction of rotation and shortly before-

Fig. 5 is a block diagram of a control system for selecting a switch41 via a feeler roller42

Also shorten a penultimate feed interval. 35 end of the return stroke of the knife of the trimming shears

F i g. 1 and 2 show an inside scissor-close. As a result, a relay 44 is energized, displaced in line with the roller _{table rollers 2} , which closes the switch 46 in the network 38 and the motors of the feed means D 2 designated with the face trimmer D ₁ and a stationary trimming V , which are set up opposite a double switches. The switch 41 opens under Federpel-Trimming Shears. In the area of double pressure 40 automatically when the cam disk 40 releases the trimming shears, the sheets are released by pairs of buttons 42.

Driving rollers 4 and 6 clamped and absolutely edging- Since the front end of the sheet is scooped straight forward, after which the continuous must be, it is provided that the feed means, trimming shears perform their cuts. The normally a fixed feed shortly behind the double trimming scissors is a 45 away according to the knife length of the Be><ium dividing scissors T , which run behind the knife level shears, are arbitrarily stopped has a pair of driving rollers 8 to be able to use the last one . This is done by a push button 48, through which the end of the sheet metal, when it has left the drive rollers 6, the relay 44 is de-energized, even if it is still to be pulled through. At least the roller table rollers, the cam disk 40, the switch 41 closed within the dividing scissors T are namely loose rollers. 50 holds. By pressing the push button 48, a pair of feeler rollers 10 in front of the knife level opens by themselves for this purpose not only the switch SO, which is driven by a roller, is used for measurement, but also the switch 52 closes in the sheet length passing through, such as still explained control circuit of a relay 54, which is when energized. 12 is an end pusher of conventional design. Switch 56 closes in the network 36, whereby the T To the sheets if they turned with their rear ends 55 of the motors TeiJschere designated the pair of driving rollers 4 have left still edge. A holding contact (not shown) holds the right to push forward, switches 52 are closed and switch 50 is open on each trimming shear, arms 14 with guide rollers 16 are arranged. Until one working cycle of the dividing scissors is finished. Sheets are therefore in the dividing shear T in the one With the implementation of the first cropping cut tension by the feed and guide means 4, 60, a length measurement must begin to a pre-6, 16 of the double trimming shears. to push the given sheet length into the upper part,

The dividing scissors T is a so-called roll cut, regardless of how many strokes the double scissors perform with the upper knife and trimming scissors moved in the path. The feed means that has a curved cutting edge. must therefore after the signal of a length measuring

The knife movements of such a known device can be stopped in a controlled manner.

Scissors are explained in more detail with reference to FIG. 3. Referring to Fig. 1 it can be seen that a

In this schematic representation, the cutting feeler rollers 10 are connected to an encoder 58,

end, curved upper knife 18, the fixed one, depending on the number of revolutions

5 6

gen counting pulses that one of the advanced sheet metal of the next feed interval V ₅ , which represent the first signal proportional to the length, must be shortened by a distance Δ F _5. This is what the first comparison device 60 forwards. In the setpoint / actual value comparison in the first comparison device 60, in the same device 60, the actual value of the sheet length passed through goes from a preselector 62 to the pulse sum as a desired partial SF ₁ + F ₂ + F ₃ 4- F ₄ + (F ₅ - Δ F ₆ ) as the first signal length proportional second signal. By using the desired lead length L _F as a preset comparator 60 to compare the first signal with the previous second signal. When the zero-given second signal is continuously compared, comparison is done by closing the switch 66 in the comparison device 60 via the line 64 a device 60, the feed is stopped and the dividing shear pulse is given to stop the feed means, io is set in motion, whereby the control is still Vorwenn Comparison results in zero. precautions can be taken, the sheet metal

Returning to the circuit diagram according to FIG. 4 slow feed rate to stop

it is to be noted that the stop impulse leading and the dividing scissors are still in the context of their inertia

Line 64 carries control current and is to be switched on in the comparison device shortly before the sheet metal comes to a standstill.

60 is closed by a switch 66 when u It can now happen that a desired

the value zero of the target / actual value comparison is reached, sheet length only slightly more than a multiple of the

d. H. the desired sheet length is due to the advance feed interval. In such a case it is

setting in device 62 has run through. When it’s not just difficult, after finishing the last one

With switch 66 closed, relay 68 is energized, full feed interval F ₄ still the small remaining

the switch 70 is open and the switch 72 is closed- ao feed precisely to drive, rather also exists

sen, who in the loop 74 of the control line 76 the risk that the cross knife of the double edging

is located. The opening of the switch 70 has the same scissors D ₁ , D ₂ to find too little "meat" and

Effect as with the push-button switch50, i.e. that slip when the remaining feed is between zero

Feed means are independent of the drive and, for example, the sheet thickness is around a

Trimming shears stopped. If switch 72 is used to indicate the limit for the risk of slipping,

close, then - as when closing the scarf- such a case must be calculated in advance, since z. B.

ters 52 - the relay 54 energized and the dividing scissors continuously the difference between the second signal L _t

automatically switched on by the stop impulse. and the first signal L _ett the run through

At the same time the sheet length can be determined and examined by the currentless relay 44,

Feed drive blocked. 30 whether there is once a difference L _F -L _e " that

So that the length measurement is exactly at the first cropping between a full pre-sweeping interval F and

cut begins, goes from the control line 76 to an F + sheet thickness d . For this, reference is made to FIG. 5b

Branch line 78 to a ballast 80 of the referenced. On the upper edge of the sheet 83

Encoder 58, which carries a voltage pulse when the feed intervals F ₁ and F ₄ correspond to

by pressing the push button 48 to trigger 35 speaking edging cuts along the line 89

of the crop cut of the switch 52 in the line 76 is shown. You can see that with a desired

is closed. This voltage impulse causes sheet length L _F after completion of the last full one

in the ballast 80 that the transmitter 58 only has a remaining feed V _{from a feed interval F 4}

Sensing roller 10 continuously output rotation signals is required in order to still reach the small hem piece 91

disconnect as the first signal during the or the next 4a. If V is smaller than the bleoh thickness d, then

The aforementioned difficulties occur, namely, the feed rate triggered by the cam disk 40

Forwards interval to the first comparison device 60. regardless of whether the severing cut is

The circuit is expedient to the effect knife immediately following the longitudinal section

completes that the comparison device 60 is already taking place or nearing the next working cycle of the

shortly before the end of the setpoint / actual value comparison 45 trimming shears, at least what the difficulty of the

sends an impulse to a relay, which affects the feed-feed in a small way,

Medium delayed to creep speed so that the metal sheets

at the final stop not yet through their according to Fig. 5b above, then one provides within the framework of

Mass force continue to run. Invention, further developed control according to

As far as has been described so far, the controller 50 provides speech 3 and 4 or according to FIG. 6 for the fact that that of the shear line for the fact that the last penultimate feed _{step F 4} is shortened so much, the feed interval independent of the continuous movement that F ₄ + V is divided into two partial feeds, the trimming shears drove, namely independently of them each is so large that the transverse knives cut safely in the revolutions of the cam disk 40, shortening trimming cut and / or the Vorbar. To explain this process, reference is made to thrust control including a delay before FIG. 5a. Here, a portion of a sufficient time to shutdown is shown sheet 81 that remains from the line 85 of a sequence of the shutdown processes.
Separating cut of the dividing scissors T from an indefinite length at the lower sheet metal edge in Fig. 5b is. The section along the line 85 indicates that when the condition is met
arbitrarily initiated by the pressure 60

button 48 (Fig. 4) is pressed. By using L _F - L _eti > F ₄ <F + d
the line 78 going voltage pulse to the

Device 80, the intermittent length measurement, the second, preset signal L _F by - Δ V corri-

Approved. Sequentially through the Vorschubinter- is yaws, ie a shortened first part feed Δ V

valle F ₁ , F ₂ , F ₃ , V _A from. 65 is set, the one under the leadership of the Nullvergleiohes

With L _f , the desired finished length of a sheet in the device 60 is the second triggering the partial cut

denotes, in which a multiple of F does not follow partial feed Δ F ₂ , both of which are sufficiently large

goes, rather the partial intersection line 87 lies within are. After the first partial feed Δ V , a

cut off shortened hem strip 93, which is followed by a residual strip 97 in the double trimming shears.

The control required to shorten the penultimate feed interval is shown in the Execution example F i g. 6. It can be seen that the elements 10, 58, 60, 62, 64, 78, 80 already explained, and the actual feed control 44, 46 and the partial scissors control 68, 72, 54, 56 are extended by a device complex, which is outlined with the dashed line 43.

Furthermore, a pulse counter 45 for partial feed lengths is also shown, which receives its pulses from the encoder of the measuring rollers 10 via line 47 and emits a pulse sum signal corresponding to the actual feed interval L _1. ,, via line 49.

The additional elements within the line 43 initially include a difference device 61 for continuously mapping the difference L ₁ L _e " (FIG. 5b) from the signals of the preselector 62 and the transmitter 58 as well as a second downstream comparison device or a discriminator 63 to determine whether at some point the condition

L _r - L _ell > V ίζ V Λ d

is fulfilled, that is, after a last advance, z. B. K ₄ , too small a Resivorschuh V < d remains. If this is the case, an impulse is sent via the line 65 to the changeover switch 67 and switches the switch 69 from the normal position shown, secured by spring pressure or the like, to the contact 71. In the normal position of the switch 69, the control variable V corresponding to the full feed length is that according to FIG. 4 is inserted through the control disk 40, 41, connected via the line 73 to a third comparator 75 to zero comparison VV _ell , whereby the normal feed control 44, 46 is actuated via the line 77 for full feed lengths. In addition, a line 84 goes from the feed device 40, 41 to a summation device 86 in which the value d coming from the preselector 88 is added to V. This sum V ♦ d goes to the second comparison device 63

In the switching position of the switch 69 on contact 71, a preselector 79 for the control variable of the shortened first partial advance length 1 V _{1 is connected} to the comparison device 75. Since each time a feed is stopped, the feed control 44, 46 sends a pulse to clear the pulse sum in the counter 45 via the line 82, the line 49 constantly contains the actual value V _c "of the sheet feed within a feed interval. By setting this value V is _ell now compared with the value Δ V _1, of a full feed interval V is preset at 79 to about half, the third comparison unit 75 now supplies a premature Still reset pulse so that the trimming shears ^ separated, only the hem strip 93 .

Soon after the partial feed Δ V ₁ begins, the difference L _t · - L _ei! in the devices 61 and 63 less than V, ie the pulse going over the line 65 goes out, the switch 69 falls into the

ίο normal position back, and the control is set to “full feed intervals”. However, it is now overwritten by the zero comparison in the first comparison device 60, which sends a pulse via line 64 at Lp - L _{cll to} both the feed control 44, 46 to stop the remaining feed Λ V \ and to the dividing shear control 68, 72, 54,56 for triggering the partial cut delivers.

The control of FIG. 6 in connection with Fig. 5b is based on the difference

ao L ₁ L ₁ ,,, to conclude on a last, too small residual feed V ' and then to divide the remaining total feed into two partial feeds until the desired lead length is reached. Of course, there are other ways to find a solution

As the task of providing two last, roughly equal part feeds for each finished length L _{f, e.g.} B. by computationally investigating whether a comparison of L ₁ with all possible "-fold feed intervals results in a residual amount V that is smaller than an" too small "amount d . Generally speaking, the invention therefore comprises a controller according to claim 3.

Furthermore, the amount d was defined as the sheet thickness. If, however, the trimming shears do not have one-sided. but only have cross knives on the outlet side (British patent specification 991 343), which means that the problem of the unsafe cross knife cut does not arise if the residual feed V is too small, then d is chosen solely from the point of view of setting a sufficiently long last partial feed. “Sufficiently long” is to be understood as a feed in which the feed motors are given time, depending on the path from a constant speed that has been run up - namely by a setpoint / actual value comparison, e.g. B. to /., L, "- so specifically stopped / u that the desired feed length is exactly obtained.

In this respect, the special feed tax university; according to FIG. 5 and claims 3 and 4 independently

whether the dividing scissors are roll cut scissors or not, and whether the sheets are pushed forward by drive rollers be or otherwise, if only the scissors section without free outlet close behind the opposite one Trimming shears is arranged.

For this purpose 2 sheets of drawings

409509/156

Claims (2)

Patent claims: 1. Control for a shear line for trimming and dividing sheet metal, in particular heavy sheet metal, consisting of long knife trimming shears with cross knives for cutting off the hem strips and a short distance downstream, the sheet feed by at least one of the knife movements of the continuously driven trimming shears dependent on actuatable driving roller pair or the like. Feeding means takes place at normally equal intervals, which can be shortened by arbitrary intervention 'by stopping the sheet feed, with a measuring device to determine the sheet length passing through the dividing shears after an initial crop cut in feed intervals and a device for path-dependent automatic stopping of the sheet feed and switching on the dividing shears when the desired finished length is reached, characterized by a device (61, 63) for calculating the last one in advance to achieve the desired finished length (L _F ) required feed interval (F ') and to compare this last feed interval with a predetermined, a minimum feed interval that is greater than the sheet thickness (d) . proportional value and with a device for extending the last feed interval (F ') at the expense of the penultimate feed interval (F ₄ ) such that the two last feed intervals do not fall below the value of the predetermined minimum feed interval. 2. Control according to claim 1, with a device (10) which is switched on by an initial Schopfsohnitt the TeU shears (7 ") for generating a first signal proportional to the sheet length (L _1. ,,) which is then advanced in one or more intervals, a preselection device (62) for storing a second signal proportional to the desired finished length (L _F ) and a first comparison device (60) for generating a pulse to stop the sheet feed when the zero comparison occurs, characterized by a difference device for determining the difference between the second signal (L _F ) and the first signal (L _efl ), a second comparison device (63) to determine whether the condition L _F -L _e "> V ^ Vd is fulfilled, where F is the unabridged feed interval and d is the value corresponding to the presettable minimum feed interval (F '), and a switch (67) for temporarily switching off the control variable of the unabridged feed interval (F) from the feed control and switching on a shortened feed interval (Δ F ₁ ) corresponding control variable set in a preselector (79), which is greater than the minimum feed interval, the temporary switchover being triggered by a pulse from the second comparison device (63) takes place if it is found therein, that .. _ "j