JPS6032593B2 - Printing machine web cutting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a web cutting device for a printing machine, and particularly to one that cuts a web using a fixed blade and a rotating blade.

In this type of device, the rotary blade is generally configured so that it works side by side with the fixed blade to cut the web during one revolution, and the rotary blade stops at the initial position after cutting. This configuration is also adopted in the invention.

However, depending on the state of the web or the rotary blade, there may be cases where the web cannot be cut, and in such cases the rotary blade will stop in contact with the web.

As a result, subsequent cutting is impossible, and the web is repeatedly printed and transported without being cut, and the motor that drives the rotary blade gets heated, causing damage. Furthermore, even if cutting is performed normally, the rotary blade may not be positioned at the initial position due to the timing of the rotary blade and the means for stopping and positioning the rotary blade at the initial position, or various other conditions. There were times when I didn't get it.

If the rotary blade does not start from the set initial position, the problem is that the acceleration time of rotation is too long and a strong impact is applied to the means for positioning it to the initial position, or the acceleration time is too short and the web is not cut. occurs. The above-mentioned problematic operations are particularly likely to occur in an apparatus that cuts webs that require a large cutting force, such as continuous tags made of cardboard. Although such a problem does not occur frequently, once it occurs, it can cause damage to the device, so it is considered an extremely important issue. The present invention solves the above problem by providing a means for monitoring whether the rotary blade is at the initial position or not, and by configuring it so that if the rotary blade is not at the initial position after the cutting operation is completed, it is determined that the rotary blade has operated abnormally. The purpose of the present invention is to provide a web cutting device that solves the problem.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described along with the overall configuration of a printing machine with reference to the drawings. FIG. 1 shows the structure of the entire printing machine, and this printing machine mainly includes a feeding device 10 for the web 1, a transporting device 20 for transporting the fed web 1, a printing device 30, and a printed web. 1, and a stacker device 60 that stacks and stores the cut webs 1.

The supply device 1 for the web 1 is provided on a mounting plate 3 screwed to the printing machine main body 2.

The mounting plate 3 has a support shaft 12 that rotatably supports the supply reel 11 and a pivot shaft 14 that pivotally supports the tension lever 13. The supply reel 11 is loaded with a web 1 wound around a core 15 with its end attached. The core 15 around which the web 1 is wound is attached to the supply reel 11
It is configured to be attached to and detached from the supply reel 11 by removing one flange la, and to rotate together with the supply reel 11 in the device state. A tension roller 17 rotatably supported by a roller support 16 is provided at one end of the tension lever 13 supported by a pivot shaft 14, and the tension lever 13 is rotated counterclockwise in FIG. 1 at the other end. One end of a spring 18 is attached, which is stretched between the mounting plate 3 and the mounting plate 3 so as to bias it in the direction. Therefore, the tension roller 17 provided on the tension lever 13 presses against and tensions the web 1 guided from the supply reel 11 to the transfer path 4. Further, a limit switch SW is attached to the mounting plate 3.

This limit switch SW, is pressed by the tension lever 13 at the time when the webbing is completed, and is turned ○N to notify the end of the webbing. That is, since the end of the web 1 is attached to the core 15, there will be extreme tension between the core 15 and the transfer device 20 when the web 1 is finished. As a result, the tension lever 13 rotates significantly clockwise in FIG. 1 and presses the limit switch SW. In the present invention, as the web 1 supplied from the supply device 10 and guided to the transfer path 4, a continuous tag made of relatively thick paper is exemplified as shown in FIG.

In the middle of this web 1, a perforation la for separation is formed along the transport direction shown by the arrow, and a perforation la is formed in the middle of the web 1.
Detection holes lb are bored at equal intervals at positions corresponding to a. The portion indicated by the dashed line orthogonal to the transport direction represents the position where the cutting device 40 cuts. The cut web 1' is used as a single leaf tag having a customer part ld and a data processing part ld, which can be separated by a perforation la. Ordinary characters are printed on the customer section ld, and optically readable OCR characters are printed on the data processing section lc using a printing device. As shown in FIG. 1, the web 1 guided into the transfer passage 4
are appropriately transferred by the transfer device 20. This transfer device has a pair of transfer rollers 21 and 22 for driving and driven rollers, and the web 1 is transferred while being sandwiched between these transfer rollers 21 and 22. The driving transfer roller 21 is rotatably supported by a roller support shaft 23 fixed to the printing machine main body 2, and is driven by gears 24, 25 by a pulse motor M fixed to the printing machine main body 2.
It is rotated as appropriate via.

Further, the driven transfer roller 22 is rotatably supported by an roller support shaft 26 at one end of the lever 27 .
This lever 27 is rotatably attached to the printing machine body 2 by a pivot shaft 28, and is provided with a spring so that the driven transfer roller 22 rotates in the direction in which the driven transfer roller 22 comes into pressure contact with the driving transfer roller 21 with the web 1 in between. It is energized at 29. A transmission type photoelectric conversion detector S is installed between the transfer device 20 and the printing device 30.

This detector S, is attached to the transfer path 4, detects the detection hole lb of the web to be transferred, and outputs a signal. The amount of web 1 transferred by the transfer device 2 is:
It is determined based on the output signal from this detector S. The line printer type printing device 30 includes a printing drum 32 that is arranged to rotate constantly and has a large number of printed characters 31 on the outer periphery, and a plurality of printing hammers 33 that hammer the web 1 against the printing drum 32. There is.

Furthermore, a printing glue 34 is disposed between the web 1 and the printing drum 32 to be transported as appropriate, and a guide roller 35 is provided on the printing body 2 to guide the web 1 to the printing position.
and a guide plate 36 are provided. The printing device 30 configured as described above performs predetermined printing on the web 1 that is appropriately transferred by the transfer device 20'. Printed web 1
is cut into predetermined lengths by a fixed blade 41 of the cutting device 40 and a drum-shaped rotary blade 42 having a blade 42a in the axial direction on the outer periphery.

The fixed blade 41 is fixed to the printing machine main body 2, and the rotary blade 42 is attached to a rotating shaft 43 supported by the printing machine main body 2, and is configured to rotate together with this rotating shaft 43. A gear 44 is attached to a rotating shaft 43 that supports the rotary blade 42, and this gear 44 meshes with a gear 45 attached to the DC motor base. Therefore, the rotary blade 42
The rotating shaft 43 is rotationally driven by a DC motor M2. Further, a disk-shaped rotation control member 46 is attached to the rotation shaft 43, and this rotation control member 46 has an engaging portion 46a bent at a right angle on a part of its outer periphery.

In the normal state, that is, in the stopped state of the rotary blade 42, the rotation control member 46 engages with the engaging portion 46a so as to be sandwiched between the positioning portion 47 and the reverse rotation prevention member 48.
The rotary blade 42 is held at a proper initial position. The positioning member 47 is positioned on a support plate 49 erected on the printing machine main body 2.
It is rotatably pivoted by a shaft 50.

This positioning member 47 is connected to the engaging portion 4 of the rotation control member 46.
A wear-resistant elastic material 47a for cushioning impact is integrally provided at the portion where the holder 6a engages, and a portion of the holder 47a is integrally formed with a wear-resistant elastic member 47b. Reference numeral 51 denotes a spring that constantly biases the positioning member 47 in the clockwise direction in FIG.

In a normal state, the positioning member 47 biased by the spring 51 is stopped against the pin 52 fixed to the support plate 49, and in this state, the engaging portion 46a of the rotation control member 46 is pressed against the elastic member 47a. can be engaged with the part. Furthermore, a plunger of an electromagnet 53 attached to the support plate 49 is connected to the positioning member 47 .

Due to the operation of the electromagnet 53, the positioning member 47 rotates counterclockwise in FIG. Go off track. In this state, the photoelectric detector S2 attached to the support plate 49 detects a part of the positioning member 47, and the supporting portion 47b is located within the rotation locus of the engaging portion 46a. Reversal prevention member 48
The spring 5 is such that one end is pivotally connected to the positioning member 47 and the other end engages with the engaging portion 46a of the rotation control member 46.
4 in the clockwise direction in FIG.

The reverse rotation prevention section 48 biased by the spring 54 is normally stopped against a stopper 47c formed in the positioning section 47. In this state, the engaging portion 46
The distance between the other end of the anti-reverse member 48 that engages with the elastic member 47a of the positioning portion 47 is set to be slightly wider than the width of the engaging portion 46a in the rotational direction. As shown in FIG. 3, a timing belt 5 is attached to one end of the rotary shaft 43 to which the rotary blade 42 and the rotation control section 46 are attached.
9 pulley 58 is being rotated.

Further, three control panels 55, 56, and 57 provided at appropriate intervals are fixed to the other end of this rotating shaft 43, and rotate together with the rotating shaft 43. Each control panel 5
There is one notch 5 near the outer periphery of each of 5, 56, and 57.
5a, 56a, and 57a are formed. The control board 5
5, 56, and 57 are monitored by transmission-type photoelectric converters S3, S4, and S5, which are rotated in an appropriate structure in the printing machine main body 2, respectively.

Specifically, the notch 55a of the control panel 55 is set at a position where it is detected by the detector S3 when the rotary blade 42 and the rotation control member 46 are at the initial position as shown in FIG. Further, the cutout portion 56a of the control panel 56 is detected by the detector S4 when the engagement portion 46a of the rotation control member 46 exceeds the elastic material 47a portion of the positioning member 47, and the cutout portion 57a of the control panel 57 is detected by the detector S4. are respectively set at positions detected by the detector S5 immediately before the web 1 is cut. The web 1 cut by the cutting device 40 is pressed upward by the driving and driven delivery rollers 61 and 62, the housing section 63 for the web 1, and the biasing force of the spring 64. It is supplied to a stacker device 60 having a pressing section 65 that does.

The driving delivery roller 61 is connected to the rotating shaft 43 via the aforementioned pulley 58 and timing belt 59, and the driven delivery roller 62 is in direct contact with the driving delivery roller 61. Each of these delivery rollers 61 and 62 is inserted into the housing section 6 from inside the printing machine main body 2 with the cut web 1 in between.
Send within 3 days. Then, the webs 1 fed into the storage section 63 are sequentially stacked and stored. Next, a circuit for controlling the printing machine constructed as described above will be explained with reference to FIG.

Reference number 7 indicates a CPU, and this CPU 70 is connected by a bus line 71 to a RAM 72 mainly used as a buffer storage circuit, a ROM 73 for program storage, and an interface circuit 74. The timers T, , T2, and T3 are each connected to the interface circuit 74 so as to be able to operate based on a command signal from the CPU 70.

Also, there is a start switch SW2 for starting the operation of the entire printing machine, and a reverse operation switch SW for the DC motor M2.
3 and the web end detection switch SW.3 described using FIGS. 1 and 3. and each detector S, , S3, S4 is also C
They are each connected to an interface circuit 74 so that their output signals can be checked by the PU 70. Furthermore, the electromagnet 53 shown in FIG. 1 is connected to the interface circuit 74 via an electromagnet drive circuit 75, and the web end indicator lamp L and the cutting abnormality indicator lamp of the cutting device 40 are connected to the lamp drive circuit 76, respectively. 77. The first, second, and third input terminals of the DC motor drive circuit 78 are connected to the interface circuit 74, the detector S2, and the detector S5, respectively, and the output terminal is connected to the first input terminal of the forward/reverse rotation control circuit 79. has been done.

The second input terminal of the forward/reverse rotation control circuit 79 is connected to the interface circuit 74 to receive the forward/reverse rotation selection signal P from the CPU 70, and the output terminal is connected to the DC motor M2 described in FIG. It is connected to the. A D-type flip-flop circuit FF, for storing whether or not the rotary blade 42 shown in FIGS. 1 and 3 has made one revolution, is as follows:
The set input terminal, reset input terminal, and Q output terminal are connected to the interface circuit 74, the clock input terminal is connected to the detector S3, and the D input terminal is grounded. To rotate the DC motor M2 in the forward direction, first
A control signal P instructing forward rotation is supplied from the PU 70 to the forward rotation/reverse rotation control circuit 79 through the interface circuit 74, and a disconnection command signal P2 is supplied to the electromagnet drive circuit 75.

The electromagnet drive circuit 75 excites the electromagnet 53 based on the cutting command signal P2. As a result, the positioning member 47 shown in FIG. 1 is driven by the electromagnet 53, and a signal is output from the detector S2. Based on this output signal, the DC motor drive circuit 78 starts the DC motor M2, and the rotary blade 42 and the rotation control member 46 shown in FIG. 1 rotate together with the rotary shaft 43 in the direction of the arrow. Then, at the time when a signal is output from the detection Aoi S4, the CPU 7 checks the signal of Makoto Kawa, and supplies the electromagnet drive circuit 75 with a signal for demagnetizing the electromagnet 53 so as to return the positioning member 47. At this point, even if the magnetization of the electromagnet 53 causes a delay in the return of the positioning member 47 by the spring 51, the engaging portion 46a of the rotation control member 46 will not hit the supporting portion 47b of the positioning member 47. By pressing as if
The positioning member 47 is forced to return. Following the output signal from detector S4, a signal is output from detector S5.

The DC motor drive circuit 78 stops the DC motor M2 based on the output signal from the detector S5. Therefore,
The rotary blade 42, the rotation control member 46, etc. then cut the web by rotating by inertia, and after pushing away the reverse rotation control member 48 at the engaging portion 46a of the rotation control member 46, stop at the initial position. do. Further, the reverse rotation of the DC motor M2 is performed in order to return the rotary blade 42 to the initial position when the rotary blade 42 is not at the initial position in a stationary state, that is, in an abnormal state.

If the rotary blade 42 is not at the initial position in a stationary state,
Since no signal is output from the detector S3, the state of the CPU 7 is determined and the lamp drive circuit 77 is operated to turn on the cutting abnormality display lamp L2. The operator confirms that the cutting abnormality display lamp L2 is lit and operates the reverse rotation switch SW3. By operating the reverse operation switch SW3, the CPU 70 supplies a control signal P, instructing reverse rotation to the forward/reverse rotation control circuit 79, and also supplies a drive command signal P3 to the DC motor drive circuit 78, so that the DC motor M2 reverses. do. When the rotary blade 42 returns to its initial state due to the reverse rotation of the DC motor M2, that is, when the detector S
3, the CPU 70 supplies a stop command signal P4 to the DC motor drive circuit 78, and the DC motor stops. Incidentally, the flip-flop circuit FF is set in advance by the CPU 70 and is connected to the rotary blade 42.
When the detector S3 operates normally and returns to the initial position, a reset state is entered when a signal is output from the detector S3.

That is, if the rotary blade 42, the rotation control member 46, etc. cannot rotate due to special circumstances, the flip-flop circuit FF remains set. Next, a circuit for driving the aforementioned pulse motor M will be explained.

80 is a pulse oscillator, and the output terminal of this pulse oscillator 80 is connected to one input terminal of a two-input AND gate circuit 81.

The other input terminal of the AND gate circuit 81 is connected to the interface circuit 74, and the output terminal is the clock input terminal of the D-type flip-flop circuit FF2 and the input terminal of the inverter 82.
and an interface circuit 74, respectively. The output terminal of this inverter 82 is connected to the clock input terminal of a D-type flip-flop circuit FF3. The Q output terminal of the flip-flop circuit FF2 is connected to one input terminal of the buffer circuit 83 and the exclusive OR gate circuit 84, and the Q output terminal is connected to the buffer circuit 83 and the D input terminal, respectively. The other input terminal of the above exclusive or gate circuit 84 is connected to the interface circuit 74,
The output terminal is connected to the D input terminal of flip-flop circuit FF3. And flip-flop circuit FF3
The Q and Q output terminals of are connected to a buffer circuit 83, respectively. The buffer circuit 83 is a flip-flop circuit FF.
2 Q output terminal, Q and flip-flop circuit FF3
It is configured to supply current to the first, first, third, and fourth input terminals of the pulse mode M, respectively, based on the Q output terminal of the pulse mode M, and each layer number input from the Q output terminal. The circuit for driving the pulse motor M operates as follows.

First, as shown in FIG. 5, the forward/reverse rotation selection signal P5 supplied from the CPU 70 to the exclusive OR gate circuit 84 becomes "L" level, and the pulse motor drive signal P6 is supplied from the CPU 70 to the AND gate circuit 81. When the gate is opened, the pulse motor M rotates in the normal direction (as indicated by arrow C in FIG. 4).

That is, under this condition, each flip-flop circuit FF2
, FF3 operate as shown by A in FIG. 5, and the pulse motor M continues to rotate normally while the pulse motor drive signal P6 is supplied from the CPU 70. Further, the forward rotation/reverse rotation selection signal P5 supplied from the CPU 70 to the exclusive OR gate circuit 84 becomes “H” level, and the CPU 70
A pulse motor drive signal P6 is sent to the AND gate circuit 81 from
When the pulse motor M is supplied and the gate is opened, the pulse motor M rotates in reverse. That is, under this condition, each flip-flop circuit FF2, FF3 operates as shown by B in FIG.
continues to reverse as long as is supplied. Next, the operation of the circuit controlling the printing machine will be explained with reference to the flowchart shown in FIG. First, a case where the cutting device 40 operates normally will be described.

First, at the start, each flip-flop circuit FF. ，
FF2, FF3, each timer T. , L, t, and other circuits are set to initial states. After the entire circuit is set to the initial state, it is determined whether or not the start switch SW2 is pressed, and if it is, this determination is repeated until it is pressed. Then, when the start switch SW2 is pressed, the detector S. Gweb 1
A determination is made as to whether or not a signal is being output by detecting the detection hole lb.

If there is no output signal, the web end detection subroutine is executed directly, and if there is an output signal, the web 1
After the web is retreated by reversing the pulse motor M by enough N pulses to cause the detection hole lb to be removed from the detection position of the detector S, a subroutine for detecting the end of the web is executed. The subroutine for detecting the end of the web is shown in FIG. That is, first, the state of the limit switch SW is determined, and if it is not turned on, it is assumed that the web remains, and the web end indicator lamp L is turned FF, and then the process moves to the next step. In addition, when the limit switch SW is turned on, the timer T is set for the time t.
, the state of the limit switch SW is determined again. Here, if the state of the limit switch SW, has changed and it is OFF, turn off the web end indicator L, and move on to the next step; if it is ON again, the web end indicator L, , and then return to step ■. In this web breakage detection, when the limit switch SW is turned on, the state of the limit switch is determined again after a predetermined time t by the timer T has elapsed. Therefore, if the limit switch SW is mistakenly turned on for a moment, it is not determined that the web has ended. If it is determined by the above subroutine that the web 1 has not finished, the pulse motor M is driven in normal rotation and the web 1 is
moves forward.

Even during this normal rotation, the state of the detector S is determined for each step of the pulse motor M, and a subroutine for detecting the end of the web is executed. Then, at the time when the detector S detects the detection hole lb of the web 1 and outputs a signal, the printing position in the first column indicated by Data "1" in FIG. 2 is set. As mentioned above, when setting the printing position for the first row from the initial state, for example, in a case where the detector S detects the rear end portion of the detection hole lb of the web 1 in the transport direction. Also, the web 1 is once reversely transported and then moved forward to the detector S. When the detection hole lb is detected again, the transfer is stopped.

Therefore, the position where the detector S detects the front end of the detection hole 1b in the transport direction always becomes the printing position in the first row, so that the printing position is accurately positioned. When a signal is output from the detector S, and the printing position of the first column is set, the detector S3
The states of the flip-flop circuit FF and the flip-flop circuit FF are determined.

That is, if the rotary blade 42 shown in FIG. 2 is at the initial position, a signal is output from the detector S3, and if the rotary blade 42 has rotated normally once during the previous cutting process, the flip-flop circuit FF, is in a reset state.
If the rotary blade 42 operates normally and is at the initial position, the web end detection subroutine is executed again, and then the first column, that is, Data "1" is printed.

After printing, the pulse motor M rotates by N2/finless to transport the web 1 by one digit, and then it is determined whether printing of all columns to be printed has been completed. If the web has not finished, detect the end of the web, print the next column (for example, the second
After the column indicated by Data "2" in the figure) and the web 1 are transferred, it is again determined whether printing of all columns has been completed. When all the information to be printed is printed in the area of the web 1 corresponding to one tag in this way, a subroutine for detecting the end of the web is executed, and the web is fed.

While the web 1 is being fed, the pulse motor M checks the output signal from the detector S at each step, and executes a subroutine for detecting the end of the web.
Then, when the detector S detects the detection hole lb of the web 1, the feeding of the web 1 is stopped.

After the feed stops, the CPU 70 outputs a cutting command signal P2 to start cutting the web 1 described above, and the flip-flop circuit FF is set, and the timer T is set.
2 drive is started. This timer L is set to time out after a time t2, which is sufficient for the rotary blade 42 to make one revolution and return to its initial position, has elapsed. After cutting the web 1 and starting the timer T2, it is determined whether all the information to be printed has been completed.

Based on this judgment, if the same information is to be printed on the web 1 corresponding to the next tag, printing, transport, and cutting are performed again after determining the state of the detector S3 and the flip-flop circuit FF. Ru. When all printing is completed, the process returns to the process of determining whether the start switch SW2 has been pressed or not. Next, during the cutting process, the rotary blade 42 stops at the pre-cutting or post-cutting position and does not return to the initial position, which is the first abnormal cutting state, and an abnormal load on the rotary blade 42 causes the rotary blade to stop. The operation in the second abnormal cutting state, such as the case where 42 does not rotate at all, will be explained.

First, in the first abnormal cutting state in which the rotary blade 42 stops midway and is not at the initial position, no signal is output from the detector S3, so this is confirmed in the process of determining the output signal of the detector S3.

If there is no output signal from the detector S3 in this judgment, it is judged whether the timer L has timed up or not. If the timer T2 has not timed up, the state of the detector S3 is repeatedly determined. If there is no output signal from the detector S3 and the timer L times up, it is determined that the rotary blade 42 has stopped midway, and the power supply to the DC motor is stopped and the electromagnet 5
After the demagnetization of step 3 is completed, the cutting abnormality indicator lamp L is lit. Furthermore, in the second abnormal cutting state in which the rotary blade 42 does not rotate at all, there is no change in the output signal from the detector S3, so the flip-flop circuit FF remains set.

Therefore, the second abnormal disconnection state is confirmed in the process of determining the output signal of the flip-flop circuit FF. In this judgment, the flip-flop circuit FF,
If T2 is in the set state, it is determined whether or not timer T2 is time mapping. If timer L has not timed up, the state of flip-flop circuit FF is repeatedly determined. If the flip-flop circuit FF is set and the timer T2 times out, it is determined that the rotary blade 42 has not rotated at all.

When this second disconnection abnormal state is determined, a flag F for the flip-flop circuit FF built in the CPU 70 is activated.
After setting a, the power supply to the DC motor M2 is stopped, the electromagnet 53 is demagnetized, and the cutting abnormality display lamp is turned on, as in the first abnormal cutting state. The cutting abnormality display lamp L2 is lit in either the first or second abnormal cutting state, but after the abnormal cutting lamp L2 is lit, the reverse operation switch SW3 for reversing the DC motor M2 is pressed. A judgment is made as to whether the

If it is not pressed, this determination is made repeatedly until it is pressed. Then, when the reverse rotation operation switch SW3 is pressed, the presence or absence of an output signal from the detector S3 is determined again. If the rotary blade 42 is not at the initial position, there is no output signal from the detector S3, and it is determined whether the web retreat flag Fb is set or not.

Since the web retraction flag Fb is not set in this first judgment, the pulse motor M is reversed by N3 pulses, and the web 1 is retracted to a position where there is no problem with the reversal of the rotary blade 42. And web retreat flag Fb
After setting, the rotary blade 42 is reversed by reversing the DC motor M2 by the drive time t3 of the timer T3. After this reversal, the process returns to the process of determining whether or not the reversal operation switch SW3 is pressed. Then, the reverse rotation operation switch SW3 continues to be pressed and a signal is output from the detector S3. If there is no signal, the state of the web backward flag Fb is determined again.

At the time of this judgment from the second time onwards, since the web retreat flag Fb is set, the direct current motor rotation is directly reversed. When the rotary blade 42 returns to its initial position in this manner, a signal is output from the detector S3 and the flip-flop circuit FF is reset.

Also, when the output signal from this detector S3 is confirmed,
After the web retreat flag Fb is reset, it is determined whether the flag Fa for the flip-flop circuit FF is set. If the flag Fa is set in this determination, the process returns to the determination process of whether or not the start switch SW2 is pressed, and the disconnection abnormality lamp L2 continues to be lit. Therefore, the operator confirms this state to be the second abnormal state and takes appropriate measures. Furthermore, if the flag Fa is not set, it is the first abnormal state and the abnormal state has been resolved, so the cutting abnormality display lamp L2 is turned off and the flag Fa is reset. . Then, return to the process of determining whether the start switch SW2 is pressed or not,
A special period is maintained until the start switch SW2 is pressed. As described above, the present invention is configured such that the rotary blade at the initial position is rotated in the normal direction to cut the web, and when the rotary blade performs an abnormal cutting operation, the rotary blade is rotated in the reverse direction to return to the initial position.

Therefore, if an abnormal cutting situation occurs in which the web is not cut but is fixed in the gap between the fixed blade and the rotating blade,
By reversing the rotary blade, the rotary blade can be smoothly and reliably returned to its initial state, and the abnormal cutting state can be resolved.

As a result, the rotary blade can be restarted from the initial position to perform a stable weave cutting operation, and the rotary blade drive motor is not overloaded and damaged. BRIEF DESCRIPTION OF THE DRAWINGS Each drawing shows an embodiment of the present invention. FIG. 1 is a partial longitudinal side view showing the structure of the entire printing machine, FIG. 2 is a partial perspective view showing an example of the web, and FIG. Figure 3 is a perspective view showing the relationship between each control board that rotates with the rotary blade and the detector, Figure 4 is the control circuit of the printing machine, Figure 5 is a timing chart of the circuit that drives the pulse motor, and Figure 6 is the timing chart of the circuit that drives the pulse motor. FIG. 7 is a flowchart for explaining the operation of the printing machine as a whole. FIG. 7 is a flowchart showing a subroutine for detecting the end of the web.

In the drawings, 1...web, 40...cutting device, 41...
... Fixed blade, 42... Rotating blade, 46... Rotation control member, 47... Positioning member, S3... Detector (monitoring means).

Figure 2 Figure 3 Figure 5 Figure 1 Figure 6 Figure 4 Figure 7

Claims (1)

[Claims] 1. A web cutting device for a printing machine that cuts a web using a fixed blade and a rotating blade, including means for positioning the rotating blade at an initial position, and means for rotating the rotating blade at the initial position in the normal direction to cut the web. a monitoring means for determining whether or not the rotary blade is at the initial position and monitoring abnormal cutting operation of the rotary blade; and when the rotary blade performs abnormal cutting operation, the rotary blade is reversed to return to the initial position. A web cutting device for a printing machine, characterized in that it has a means for cutting a web.