DE2246034A1 - DEVICE FOR MEASURING THE STOP TIME ON PRESSES - Google Patents

Description

Qms \ Q lÖe'lSSe ' 5602 LANGEN BERG (Rhelnl). the

, 'Bökenbusch 41

Patent attorneys. ^

Patent application

Erwin Sip company; k. .-Optics-electronics, 7808 Waldkirch, An der Allee 7-9 .. "'' \"

Device for measuring the stop time on presses.

The invention / relates to an apparatus for measuring the stop ^{^:} time and / or the ΓΓachlaufweges of presses. · ■ '■: ..

The "stop time" of a press is the period of time between the stop command and standstill of the press ram. The next way is the distance covered during the stop time. "

Dei *, exact value of the stop time and the overrun distance of a mechanical'or The press operated by hytiraul is special Meaning for "the correct arrangement of controls or protective devices for the press. , ·.;. .

Control elements for presses are generally designed so that the hands are% d | jß * during the dangerous closing movement of the operator at the controls, for example ' I pressure switches, are compulsorily bound. In the so-called Zweihahdeinrückung this is achieved by simultaneously using two pressure switches for the entire duration of the closing

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Poetecheckkonto Essen 47247 · Commerzbank AG Düsseldorf, Oepoeltenkasse Hauptbahnhof

. must "be actuated motion When both switches are operated simultaneously, a closing movement is initiated:.. If the operator 'during the closing movement by Somehow' nachgreift ■■ 'v / oak circumstances in'das tool, · that is, in the danger zone. , at least one pressure switch is automatically no longer actuated and the press is stopped. Reaching during the closing movement can, for example, be caused by the fact that the operator notices an irregularity at the last moment

It is now important that the press ram comes to a standstill. comes before the operator's hand gets into the danger area ', or at least only a minimal amount to none';;. . The path leading to the injury. The press stop time must therefore be shorter than the "grip time". The grip time is the time required for the path to be covered, in the case from the pressure switch to the danger area; is done. One calculates with an average handle speed; • ability of 1.8 m ^: pro. Second. The grip time can be calculated from this. -.net become. Stands the stop time. a press firmly, then ", analogously, the controls must be arranged so that '; / 7 the grip time is certainly greater than the stop time." . ^v

The situation is similar with automatically operating protective devices. facilities. These are generally .light curtains, with, ": .. which a light beam periodically over a ι to be monitored 'The protective field is deleted and the light beam is interrupted photoelectrically triggers a shutdown signal. These light curtains are placed between the danger area and the operating personnel arranged. If there is an object in the protective field of the light curtain, it will be recognized and no closing movement permitted. The protective field becomes during the closing movement

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of the light curtain is broken, the Closing movement stopped. ' Again, it is important, the Stop time to know the press to keep the light curtain in sufficient To be installed at a distance from the danger zone.

The invention is based on the object of a device to properly measure the stop time of a press. ■;

The invention is also based on the object of the read, sung the stop time in such a way that a documentary Record of the result of the measurement is obtained. .

According to the invention, this object is achieved in that an Easter marking can be scanned by a photoelectric scanning device, one of these parts being attached to the ram of the press to be measured and the other being fixedly attached, and in that the output signals of the photoelectric scanning device act on a recorder with a known constant abscissa feed rate . '' ■ ''

In this way, a recording of the pulses is obtained which, when scanning, moves the pulses relative to the scanning device Easter marking to be obtained. If Easter stays the same, these impulses become increasingly broader and their distance becomes larger greater as the speed of the press ram increases slowed down. Finally it emerges in the record a (L or O) continuous signal, which indicates the standstill of the press ram. From the intervals between the pulses or their Width, the temporal course of the slide movement can be determined. '.

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224603A

The scanning device can be movable with the press ram "and" interact with a fixed grid marking. However, the latching mark is advantageously with the press ram is movable and the scanning device is fixed. .

The grid marking can be formed by a plurality of reverse-reflecting strips arranged at fixed intervals . ■ ". · '^{; :} [ . · ■'"'■■"■ ·.

It is possible that the stop signal by which the press is stopped shall be; to record in addition to the 'sampling pulses and thereby determine the stop time. Particularly However, it is advantageous if a stop signal to the. Stopping the press ram by a signal from the scanning device first recorded strips of razor pith: ia? ung is releasable. .

The press can then be switched on. As soon as the grid marking is detected by the scanning device, automatically generates a stop signal. The number of dei? then appearing impulses is a direct measure for the overtravel. -from the known speed of the abscissa feed the stop time can be determined, which runs from the first pulse to the occurrence of the continuous signal.

There can be another in a further embodiment of the invention Reverse reflective stripes be arranged at a fixed distance from the grid marking ', ·' so that it is timed before the Raster marking is captured. ' The abscissa feed can be switched on from the signal of the scanning device thus obtained be. ■ '""' "'■' - '' '■■"' "

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This .reaches, ..that the abscissa feed is autoraa- .. . table after, starting the. Press .and in. Your. to the. achievement a constant abscissa feed rate required. Time before the stop signal occurred. and with it the ... ' Start of the actual measurement is switched on. To avoid this, an unnecessarily large amount of registration paper etc. is used up.

The. electrical circuit can advantageously be constructed so that the press drive can be controlled by a flip-flop, which is triggered by a start signal. a "first input is set. and the press drive is switched on, and that the flip-F.lop. can be reset by a pulse from the scanning device at a second input. In order to ensure that the stop signal has not already been triggered by the signal from said further reverse reflective. Strip is triggered. which switches on the abscissa feed, the output signal of the scanning device can be connected to the second input of the. .Flip-rFlops, are present.; ... The output signal of the scanning device li, then continues to be applied to the set input of a monostable multivibrator that can be triggered _{by the trailing edge: of the output signal.} The second one gear of the AND gate is connected to the output of the monostable multivibrator. In such an arrangement, the AND element is initially blocked. The first signal from the scanning device is not switched through to the second input of the flip-flop. The AND element is only opened when the monostable multivibrator is triggered by the trailing edge of this first output signal. .During the switching time of the monostable. Flip-flop, which must be selected to be greater than the expected stop time of the press, the subsequent pulses are then sent to the second input of the flip-flop, the first pulse causing the flip-flop to be reset. the

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subsequent impulses at the second input of the flip-flop have no additional effect. A writing magnet can be supplied from the output of the AND element and the output of the monostable multivibrator can be used. Abscissa feed. (Paper transport) of the recorder designed as a pulse recorder can be switched on. : The paper transport is therefore stopped .:. switches through the trailing edge of the "pre-pulse" and remains ^: switched on during the switching time of the monostable toggle ^. ■ '■ · stage .. After the switching time of the monostable multivibrator has elapsed. the abscissa feed of the recorder is automatically switched off, so that a paper transport actually only. · ■. ,. essentially takes place during the measurement itself ... ^:: ■

The invention is. below using an exemplary embodiment with reference to the accompanying drawings 'mower er ■ ·'■; ■ ■ .; purifies: ... ...... .... ^: - ■■ ■ .. ■■ · .. ■ ■ ...;: ·. ■■

Fig. 1 shows schematically the structure of a measuring device:. ... device according to the invention and the associated circuit. . ' ■. ■■ tion. · ·· ■ "■. · ■ · .... · ■ ·: ■. ■■,. ■. ·.:.; -;

Fig. 2 shows various timing diagrams used in the '.; • - ·., ·. according to the invention. Device occur. . . ■

A plate 12 is attached to a press ram 10, which a grid marking 14 in the form of parallel, in the same Spaced apart reverse reflective strips 16 carries. Parallel to the strips 16 but at a distance of A further reverse reflective strip 18 is attached to this at the lower end of the plate 12. The grid marking • 14- and the strip 18 are made by means of a photoelectric Scanning device 20 scanned. This photoelectric scanning

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device can be of known construction. A light beam emanating from a light source becomes at 22 in the plane, the. Grid marking 14 and the strip 18 focused ·. · That: in the Eiiif alignment uiackreflected,. Jiicht-is gelextet · · · .by .a arranged in the beam path is sloped .. ■ th teildurchlässige'n mirror on a photoelectric 'receiver'. The output signals of the photoelectric receiver r .erscheinen 24 at an output. / ^. ■ .--- r

A manually operated pushbutton switch is used to ... Startsijgnal to a first input 28 of a flip-flop 30 given and the flip-flop 30 set thereby. The flip-flop 30 switches: a relay 32, which with a working and a break contact 3 ^ or 36. instead of the previous operating elements, such as light curtain or two-hand indentation, in which: v Press control is switched on and the downward movement of the ram 10 initiates (closing movement) of the press. . . ■

The plate 12 with the reflector 8 and the raster mark formed by the reflectors 16 is thereby attached to the photoelectric scanning device. 20 swept past. At the output 24 of the photo-electric scanning pulses appear as in line a of Fig 2. First, the pulse 18 occurs' from the inverting reflective strips 18 on pulse 18 ^r abuts ■.-This. ■ <.- with its trailing edge, a monostable multivibrator 38 at , how . ■ is represented by curve 38 'in line.c of Fig. 2. The; The monostable multivibrator 38 opens via the input 40 one element 42. The other, input 44 of the UJND element 42 is also connected via a switching amplifier 46. Output 24 of the photoelectric scanning device 20 .. Via the opened UiTD element 42, the pulses 16 '(a FIG. 2), from. the um- ■,

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U-turn reflective strips 16 originate on the second Input 48 of flip-flop 30. The first of these pulses resets flip-flop 30. This causes the relay to drop 32 and the movement of the press ram 10 is switched off. So that the movement of the press ram 10 is during the stop time t is slowed down to a standstill. The impulses 16 ' get wider, their distance gets bigger, until finally, at Standstill permanent signal at output 24 is obtained. Depending on whether the sampling point 22-then on a reverse reflective Stripes or on a space between the stripes, the output signal at output 24 is L or 0.

Through the output of the monostable multivibrator J8 (signal 38 ' Line c of Fig. 2) the paper feed is controlled via a relay 50 an impulse recorder with externally controllable paper transport switched on. By the distance between the pulse 18 'and the first of the pulses 16' ensure that when the pulses 16 'and the stop signal occur, the paper feed is at its constant and known speed has reached. . ·

The output of the AND gate 42 (line b, Fig. 2) is also given to the writing magnet 52 of the pulse writer. The pulse recorder thus delivers a recording corresponding to line e of FIG. 2. The stop time t can be determined from this as indicated. The number of pulses' multiplied with the known spacing of the reverse reflective strips 16 provides the overtravel.

Line d in FIG. 2 shows the switching state of the flip-flop 30. This is activated via the switch 26 at any time set and via input 48 when the first im-

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pulses 16 'postponed .. Vie from line c in Fig. 2.-visible is, the monostable multivibrator .. 38 falls after a predetermined time, which is greater than the expected stop time, in your; Initial state back. This also increases the paper advance stopped.

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Claims (1)

2246-34 Claims · ·. '■' ■ '' ■ £ · ·/1. ! Device for measuring the stop time and / sder of the after-run way on presses, characterized in that a raster marking (14-) can be scanned by a photoelectric scanning device (20), one of these parts being on the The ram (10) of the press to be measured and the other is fixedly attached, and that the output signals of the ■. photoelectric scanning device (20) apply a writer "" with a known constant abscissa feed. 2. Apparatus according to claim 1, dadux'ch characterized in that the Hasty marking (14-) formed by a plurality of reverse-reflecting strips (16) arranged at fixed intervals will. · .. '.' 5. Apparatus according to claim 2, characterized in that a Stop signal for stopping the press ram (10) by a signal (16 ') of the scanning device (20) from the first detected Strip of the grid marking (14 ·) can be triggered. 4 ·. Device according to claim 3, characterized in that a further reverse reflective strip (18) is arranged at a fixed distance from the grid marking (14-) so that it is detected temporally before the raster marking (14-) and that of the signal (18 ') obtained thereby from the scanning device (20) the abscissa feed (50) can be switched on. 5. Device according to claim 3 or 4, characterized in that that the press drive can be controlled by a flip-flop (30), 409813/0136 - 11 - which is set by a start signal (26) at a first input (28) and switches on the press drive, and that the flip-flop (30) is connected to a second input (48) by a pulse (16 ') from the scanning device (20) resettable ■ '·' is · '■; . '■ / ■ ... ■. ■■ '. · ■ ··. ·. ■■■■ 6. Device according to claims 4 and 5-, characterized in that the output signal (a, Fig. 2) of the. Scanning device (20) via a peeling amplifier (46) and a UHD element (42) at the second input (48) of the flip-flop (30) that the output signal of the scanning device (20) continues to be applied the set input of a through the back flap of the output signal Äöstbaren monostable flip-flop (38) and that the second input (40) of the AND element (42) is connected to the output of the mpnostable multivibrator (38). 7. gate direction according to claim 6, characterized in that of the output of the AND gate (42) a writing magnet (52) and of the output of the monostable multivibrator (38) of the abscissa. feed paper transport (50) of the writer designed as a pulse writer can be switched on. 0 9.8 13/0136