JPH0351222B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a protection device for a printing press, such as a rotary printing press, which solves problems associated with paper breakage.

[Background Art] In a rotary printing press, if a printing paper is cut due to a catch or the like while being printed through a plurality of printing units, the subsequent printing paper is wrapped around the printing roller etc. multiple times. Yuruburan winding may occur. For this reason, normally, multiple paper breakage detectors and paper cutters are installed in the path through which printing paper passes, and when a paper breakage is detected by the paper breakage detector, the paper cutter operates to detect, for example, the location of the paper breakage. Measures are taken to separate the front and back of the paper to prevent the cut paper from getting wrapped around rollers or the like.

However, conventional paper-out detectors have a circuit configuration that simply optically detects the presence or absence of printing paper and outputs a paper-out detection signal when there is no printing machine. When there are multiple ways to pass the paper through, if the printed paper does not pass through some paper break detectors, a paper break detection signal will be constantly output from that paper break detector, which will cause the operation of these paper break detectors to be I had to turn it off with another switch.

However, sometimes they forgot to turn off another switch and stopped the machine, or the paper cutting machine often cut unnecessary paper.

[Object of the invention] The object of the invention is to
It is an object of the present invention to provide a protection device for a printing press that solves the above-mentioned problems associated with running out of paper.

[Structure of the Invention] Therefore, the present invention provides a plurality of paper breakage detectors and a paper cutter, respectively, in a printing paper path in which there are a plurality of ways of passing the printing paper through the printing section, and In the protection device for a printing press, the paper cutter is activated by a paper cutout detection signal, and the paper cutter includes a paper detection element that outputs a paper detection signal when there is printing paper; A flip-flop is set by the paper detection signal from the paper detection element, an AND circuit receives the output from the flip-flop and the inverted signal from the paper detection element, and the output from the AND circuit detects paper out for a predetermined period of time. This circuit is constructed from a circuit that outputs a signal and resets the flip-flop.

[Example] Figures 1A and B show the entire system of the printing press of this example. Each figure shows a state in which sheets of printing paper are being printed simultaneously. The printing machine is equipped with six printing units U1 to U6, and one or more printing papers W pulled out from paper feed units R1 to R4 are printed by selectively passing through the plurality of printing units U1 to U6. After that, they are folded into folding machine F. Here, in the path through which each printing paper W passes, there are a plurality of paper breakage detectors D ₁ to Dn for detecting paper breakage of each printing paper W, and a plurality of paper cutting machines.
S ₁ to Sn are installed respectively.

FIG. 2 shows the circuit of each of the paper breakage detectors D ₁ to Dn. Each of the paper-out detectors D ₁ to Dn includes a paper detection element 11 that optically detects the presence or absence of printing paper W;
A flip-flop 12 is set by the output from the paper detecting element 11, and a signal from the output terminal Q of this flip-flop 12 is used as one input, and the output from the paper detecting element 11 is inverted by a not circuit 13. and a one-shot multivibrator 15 which outputs a paper-out detection signal for a preset time based on the output from the AND circuit 14 and resets the flip-flop 12. There is. The paper detection element 11 includes a light source 16 that emits light toward the surface through which the printing paper W passes.
and a phototransistor that receives the reflected light from the printing paper W and provides a paper detection signal of the "H" level when the printing paper W is present and a signal of the "L" level when the printing paper W is absent to the flip-flop 12. It consists of 17.

Now, as shown in FIG. 3, when the printing paper W is in a normal state, that is, in a certain state, the paper detection element 11 outputs an "H" level signal. Then, due to the "H" level signal, the flip-flop 12
is set, and an "H" level signal from the output terminal Q of the flip-flop 12 is applied to one input terminal of the AND circuit 14. On the other hand, AND circuit 1
Since the other input terminal of the AND circuit 14 is given a signal obtained by inverting the "H" level signal from the paper detection element 11 by the NOT circuit 13, that is, an "L" level signal, the output of the AND circuit 14 is "L" level. ” level remains.

Here, if a paper break occurs in the printing paper W,
The output from the paper detection element 11 is inverted to the "L" level. Then, the "L" level signal is inverted by the NOT circuit 13 and then applied to the other input terminal of the AND circuit 14, so that the AND circuit 14 outputs an "H" level signal. Then,
In response to the "H" level signal from the AND circuit 14, a paper break detection signal is output for a predetermined period of time via the one-shot multivibrator 15, and the flip-flop 12 is reset. Based on this paper-out detection signal, a machine stop signal is output, and the printing press is stopped.

Therefore, since a paper out detection signal is output for a certain period of time when the printing paper W changes from a state in which it is present to a state in which it disappears, even if there are various ways in which the printing paper W passes through the printing units U1 to U6, it is possible to There is no need to use a separate switch to turn off the function of the paper break detector that prevents the printing paper W from passing through, and there is no need to forget to turn off these switches and stop the machine, or to cut unnecessary paper with the paper cutter.

FIG. 4 shows a display circuit for displaying which paper break detector D ₁ -Dn was activated first. In the figure, each paper break detector D ₁
The signals from ~Dn are applied to one input end of the corresponding AND circuits 21 ₁ ~ 21n, and are also applied to the AND circuit 23 via the OR circuit 22.
is applied to one input terminal of the . AND circuit 2
The output from the flip-flop 24 is input to the set input S of the flip-flop 24. flipflop 24
The signal from the output terminal Q of each of the AND circuits 21 ₁
~21n is applied to the other input terminal. The outputs from the AND circuits 21 ₁ to 21n are input to the set input terminals S of the corresponding flip-flops 25 ₁ to 25n, respectively. A signal based on the opening/closing of the reset switch 26 is input to the reset input terminal R of each of the flip-flops 25 ₁ to 25n. In addition, each flip-flop 25 ₁
The signals from the output terminals Q of 25n to 25n turn on the corresponding display elements 27 ₁ to 27n, respectively, and are outputted as the machine stop signal MSS via the OR circuit 28, and are outputted via the OR circuit 29 to the flip-flop 24. is reset and inverted by the NOT circuit 30, and then applied to the other input terminal of the AND circuit 23.

Now, when each of the flip-flops 25 ₁ to 25 n is in a reset state, if the paper break detector D ₁ detects a paper break and outputs an "H" level signal, the "H" level signal is outputted via the OR circuit 22 and outputs an "H" level signal. It is applied to one input terminal of the circuit 23. Here, since the "H" level signal is given to the other input terminal of the AND circuit 23, the flip-flop 24 is set by the "H" level signal from the AND circuit 23, and the output terminal of the flip-flop 24 is set. The "H" level signal from Q is applied to the other input terminal of each AND circuit 21 ₁ -21n. Then, the output from the AND circuit 21 ₁ becomes "H" level, so the flip-flop 25 ₁ is set. Then, the "H" level signal from the output terminal Q of the flip-flop 25 ₁ lights up the display element 27 ₁ and outputs the machine stop signal MSS via the OR circuit 28 . The flip-flop 24 is then reset.

When the flip-flop 24 is reset, the signal from the output terminal Q of the flip-flop 24 is inverted to the "L" level, and after that, the paper break detection signal of the "H" level is applied from the paper break detectors D ₂ to Dn. Flip-flop 25 ₂ ~ 25n
is never set. In other words, only the display elements 27 1 to 27n corresponding to the paper break detectors D ₁ to Dn that worked first are lit, and the display elements 27 ₁ to ₂₇ n corresponding to the paper break detectors D ₁ to Dn that worked after that are lit.
Since 27n is not lit, it is possible to take countermeasures by looking at the lit display elements 27 ₁ to 27n. When the reset switch 26 is pressed after the countermeasure is taken, all flip-flops 25 ₁ to 25n are reset and returned to their initial state.

Therefore, by looking at the display elements 27 ₁ to 27n, it is possible to determine which paper break detector D ₁ to Dn was activated first, making it possible to easily and quickly determine the location where the paper break has occurred. can.

FIG. 5 shows a circuit for selecting which paper cutter S ₁ -Sn is activated when each paper break detector D ₁ -Dn is activated. In the figure, signal lines 41 ₁ to 41 from the respective paper breakage detectors D ₁ to Dn
n and the signal lines 42 ₁ to 42 from the paper cutting machines S ₁ to Sn.
Selection switches 43 ₁₁ to 43nn are inserted at the intersections with 42n, respectively. Each selection switch 43 ₁₁
~43nn has its selection switch 43 ₁₁ ~43nn
Display elements 45 ₁₁ to 45 that light up when the is closed
nn are connected to each other.

Now, for example, in order to select the paper cutting machines S ₁ to Sn to be activated for the paper break detector D ₁ , select the intersection of the signal lines 42 ₁ to 42n and the signal line 41 ₁ of the paper cutting machines S ₁ to Sn to be activated. Selection switch 43 ₁₁ , 43 ₁₂
. . is closed, the selection switches 43 ₁₁ , 43 ₁₂ . . . are closed when the paper break detector D ₁ is activated.
The paper cutting machines S 1 to Sn are operated through the paper cutting machines S ₁ to Sn.

Therefore, since it is possible to select the paper cutting machines S ₁ -Sn that operate according to the respective paper-out detectors D ₁ -Dn, various ways of passing the printing paper W through the printing units U1-U6 can be selected. Even if the number of paper cutters is changed, the paper cutting machines S ₁ to Sn can be selected according to the way the various types of paper are threaded, and unnecessary cutting of paper can be prevented.

[Effects of the Invention] As described above, according to the present invention, even when there are multiple ways of passing the printing paper through the printing section, the problem of paper breakage can be solved regardless of the way the printing paper is passed through the printing unit. Machine protection equipment can be provided.

[Brief explanation of drawings]

The figures show one embodiment of the present invention, in which Fig. 1 is an explanatory diagram showing the outline of a printing press, Fig. 2 is a circuit diagram showing a paper break detector, Fig. 3 is a time chart, and Fig. 4 is an explanatory diagram showing an outline of a printing press.
The figure is a circuit diagram showing a display circuit, and FIG. 5 is a circuit diagram showing a selection circuit of a paper cutting machine. U1~U6...Printing department, W...Printing paper, _D1 ~
Dn...Paper break detector, S ₁ ~ Sn...Paper cutting machine, 1
1...Paper detection element, 12...Flip-flop,
13...Not circuit, 14...AND circuit, 15
...One-shot multivibrator, 21 ₁ ~
21n...AND circuit, 22...OR circuit, 24
...Flip-flop, 25 ₁ to 25n... Flip-flop, 27 ₁ to 27n... Display element, 4
3 ₁₁ ~ 43nn...Selection switch, 45 ₁₁ ~ 45nn
...display element.

Claims (1)

[Scope of Claims] 1. A plurality of paper breakage detectors and a paper cutter are respectively provided in a printing paper path in which there are a plurality of ways of passing the printing paper through the printing section, and a paper breakage detection signal from the paper breakage detector is provided. Accordingly, in the printing press protection device configured to operate the paper cutting machine, the paper breakage detector is configured to include a paper detection element that outputs a paper detection signal when there is printing paper, and a paper detection element that outputs a paper detection signal when there is printing paper. A flip-flop is set by the signal, an AND circuit receives the output from the flip-flop and the inverted signal from the paper detection element, and outputs a paper-out detection signal for a predetermined period of time based on the output from the AND circuit. and a circuit for resetting the flip-flop. 2. The protection device for a printing press according to claim 1, including a plurality of display elements corresponding to each of the paper breakage detectors, and a paper breakage detection signal given first among the paper breakage detection signals from each of the paper breakage detectors. 1. A protection device for a printing press, comprising a display circuit that lights up only one of the display elements corresponding to the above. 3. In the printing press protection device according to claim 2, the display circuit includes a plurality of AND circuits each receiving a paper break detection signal from each of the paper break detectors as one input, and a plurality of AND circuits each receiving a paper break detection signal from each of the paper break detectors. a plurality of first flip-flops that are set in accordance with the output of the first flip-flop to light up the display element;
The first flip-flop is reset by the set output of any one of the first flip-flops, all of the first flip-flops are reset, and a paper-out detection signal is issued from any of the paper-out detectors. 1. A protection device for a printing press, comprising a second flip-flop serving as the other input of each AND circuit. 4. The printing press protection device according to claim 1, further comprising a plurality of selection switches for selecting the paper cutting machine in accordance with a paper breakage detection signal from the paper breakage detector. Machine protection device. 5. The protection device for a printing press according to claim 4, wherein each selection switch is provided with a display element that lights up when the selection switch is closed. Machine protection device.