JP2854766B2 - Paper jam detection device in sheet-fed printing press - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a paper jam in a sheet-fed printing press.

[0002]

2. Description of the Related Art Conventionally, a sheet-fed printing press that separates and prints stacked sheets one by one is provided with a front-to-back alignment of a top sheet stacked in a stacking section. A "front fence" for performing the operation, and temporarily suspending the sheets conveyed on the feeder board (sheet conveying plate), aligning the position of the sheets in the traveling direction, and adjusting the sheets at a predetermined timing. Swing mechanism for sheets (mechanism for transferring sheets to the feed cylinder)
A "pre-applied" for handing over the sheet, a "board tape" that conveys the sheet toward the pre-applied, and a "roller" that presses the sheet being conveyed on the feeder board from above to ensure stable conveyance
And the like.

In a sheet-fed printing press having the above-described mechanism, a paper feed jam may occur due to the following reasons. The leading sheet of conveyance is twisted for some reason or is caught by some member, and is not normally conveyed. When a printed sheet is fed (for example, printing on a backing sheet), the sheet easily curls, is caught on the front fence, and is not conveyed normally. The pressure regulating roller on the feeder board does not operate normally, and the sheet is not properly conveyed on the feeder board.

[0004] When a sheet jams once in any part of the transport path due to these causes, the sheet fed from the stacking section is successively accumulated at the place where the jam occurs, and these jams occur. All sheets become waste. Further, when the accumulated sheets are sent out as a lump to a swing mechanism or a paper feed cylinder, there is a problem that the mechanism at that portion may be damaged.

As a method and an apparatus for detecting a paper-feed jam for detecting a paper-feed jam peculiar to such a sheet-fed printing press, for example, JP-B-51-32121, JP-B-3-7806.
No. 6 is known.

[0006]

However, these inventions are designed to detect an abnormality in the conveyance of a sheet and issue an abnormality alarm or the like. There is a possibility that the large number of waste sheets, the swing mechanism and peripheral devices may be damaged.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems, and when a sheet conveyance error is detected, the sheet feeding in a sheet-fed printing press is immediately stopped. It is an object of the present invention to provide a method for detecting a jam and an apparatus therefor.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a separating and sending section for separating and sending out sheets stacked on a stacking section one by one, and separating from the separating and sending section. in sheet-fed printing machine comprising a conveying unit for conveying the fed out sheet to the printing cylinder, distribution immediately before the printing cylinder
And a single sheet detection unit for detecting the presence or absence of a sheet there, and from the start of separation of the sheet by the stacking unit until the sheet arrives at the sheet detection unit. Elapsed time , previous
A time measuring unit for measuring on the basis of the serial output signal from a single sheet detecting unit, before being measured by the time measuring unit
The elapsed time and after the separation of the sheets in the
Predetermined time required for paper to arrive at the sheet detection unit
And the elapsed time is compared with the reference time.
And a stop control unit that controls the separation / delivery unit and the transport unit to stop when the interval is exceeded .

[0009]

The sheet is separated from the stacking section by the separating and sending section, sent out, conveyed by the conveying section toward the printing cylinder, and detected by the sheet detecting section to be conveyed immediately before the printing cylinder. . On the other hand, the required time from immediately after the start of separation of the sheet to the arrival at the sheet detection unit is known in advance corresponding to the mechanism of the printing press. Then, the required time (the former) known in advance is compared with the actual required time (the latter) from immediately after the start of separation until the sheet arrives at the sheet detecting unit, and the latter is larger than the former. In this case, it is determined that the conveyance is abnormal (feeding jam), and the separation / delivery unit and the conveyance unit are immediately stopped. Due to this stop, the subsequent separation and delivery of the sheet is stopped, the waste paper can be minimized, and breakage of the swing mechanism and the like can be prevented.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
The configuration of the mechanical system and the configuration of the control system will be described separately. Mechanical system First, the mechanical system will be described.

As shown in FIG. 1, the mechanical system of the sheet-fed printing press P includes a separation / delivery unit that separates the stacked sheets 3 one by one and feeds them to a printing cylinder in order from the right side of the figure. (Feeder) 1
A transport unit 11 for transporting the sheet 3 separated and transmitted from the separation and transport unit 1 toward a printing cylinder, a printing unit 21 for printing the sheet 3 transported by the transport unit 11, A paper discharge unit 31 on which the sheets 3 printed by the print unit 21 are stacked and placed; and an operation panel 4 on which an operator gives various input instructions
0 or the like.

The separation / delivery unit 1 includes a mounting table 2 which is a "stacking unit" on which sheets 3 for printing are stacked, and a vacuum suction of the sheets 3 one by one and moves back and forth to move the sheets 3 one by one. A suction foot (adsorbing member) 4 for feeding sheets to a feeder board 12 as a transport support member, and a vacuum pump 5 for generating a vacuum pressure
And a vacuum valve 6 for opening and closing the vacuum pressure of the vacuum pump 5, a suction valve 4, a vacuum valve 6, and a pipe 7 connecting the vacuum pump 5 and the like. The vacuum valve 6 includes a vacuum pump 5
Is supplied to the suction foot 4, and when the vacuum valve 6 is turned on while the vacuum pump 5 is on, the suction foot 4 sucks the sheet 3.
That is, when the printing press is rotating, a feeder solenoid (not shown), a vacuum pump 5,
When all three devices of the vacuum valve 6 are turned on, the uppermost sheet on the mounting table 2 is adsorbed to the suction foot 4 by the action of the vacuum air and is sent out from the separation sending unit 1. Reference numeral 8 denotes a front fence, which is a mechanism for aligning the uppermost stacked sheets 3 in the front-rear direction, according to the timing at which the sheets 3 are sent out to the feeder board 12. It is configured to be inclined in the paper feeding direction.

The conveying section 11 conveys the sheet 3 separated and sent from the separating / sending section 1, abuts against a front contact 16 (see FIG. 2) and temporarily stops the sheet 3, This is a device for feeding paper to the printing unit 21. Here, the front contact 16 is a device that regulates the position of the sheet conveyed on the feeder board 12 in the traveling direction and transfers the sheet to the swing mechanism 17 at a fixed timing. The paper cylinder 15 is a device for transferring a sheet to the impression cylinder 23 in the printing process.

The transport unit 11 is moved along the surface of the feeder board 12 and transports the sheet 3 toward the front pad 16. A roller 14 that presses the sheet 3 from above to stably convey the sheet 3, a swing mechanism 17 that transfers the stopped sheet abutted on the front pad 16 to the paper feed cylinder 15, and a front pad 16. A paper feed sensor (paper detection sensor) 18 that detects whether or not the sheet 3 has arrived and generates a determination signal as to whether or not the printing unit 21 enters a printing process.
(See FIG. 2), and a drawing device 19 for aligning the sheet 3 conveyed to the front pad 16 in a direction (left-right direction) perpendicular to the traveling direction. In the transport unit 11, various mechanisms for transporting the sheet 3 to the front pad 16 are driven by a power source M provided in a printing press main body, and a clutch mechanism (FIG. (Not shown), and a feeder solenoid (not shown) for controlling the clutch mechanism is provided. Then, when the feeder solenoid is turned on while the printing press body is rotating, all mechanisms for transporting the sheet 3 up to the front contact 16 are operated.

The printing unit 21 includes a blanket cylinder 22 to which a plate cylinder is attached, and an impression cylinder 23 for printing by pressing a sheet 3 passing between the blanket cylinder 22.

The paper discharge unit 31 is constituted by a mounting table 32 for sequentially loading printed sheets, and the like.
At the upper left of 1 is a pump switch 4 operated by the operator.
4, an operation panel 40 including a vacuum switch 45, a feeder switch 46, and the like (see FIG. 3) is provided. Control System Next, the control system will be described.

As shown in FIG. 3, the central control unit C
The PU 41 is input to the PU 41 via the input interface circuit 42 at a timing (285 °) immediately after the sheet arrives at the front patch 16 once per rotation of the machine (printing cylinder). Timing switch 4 arranged to fall (change from ON to OFF, see FIG. 5)
3 and a pump switch 44 for operating the vacuum pump 5
And a vacuum switch 45 for operating the vacuum valve 6 and a feeder switch 46 for operating the separation / delivery unit 1 and the transport unit 11. Also, CP
U41 via the output interface circuit 47,
A first relay 48 for turning on and off the feeder solenoid, a second relay 49 for turning on and off the vacuum valve 6, and a third relay 50 for turning on and off the vacuum pump 5 are connected. The CPU 41 is connected to a memory 51 including a RAM. here,
Reference numeral 48a is a contact of the first relay 48, and reference numeral 49a
Is a contact of the second relay 49, and reference numeral 50a is a contact of the third relay 50. Further, the CPU 41 includes a time counter.
Measuring unit (ie, counting unit 41a) and stop control unit 41b
It has. The counting unit 41a is provided in the stacking unit (that is,
After separating the sheet 3 on the stage 2), the sheet is detected
When the paper reaches the printer (ie, the paper feed sensor 18)
In the meantime, in other words, the time from when the sheet is fed by turning on the feeder solenoid, the vacuum valve 6 and the vacuum pump 5 to when the sheet arrives at the front patch 16 is measured . The stop control unit 41b is controlled by the counting unit 41a.
And the elapsed time measured Te, the sheet 3 is compared with the advance between the time defined by that standard <br/> which until arriving at the front lays 16 from the sheet feed start, from the reference time, the elapsed If the time is long, the first to third relays 48 to 50 are operated to stop the feeder solenoid, the vacuum valve 6, and the vacuum pump 5.

Now, the printing press P is rotating (step S).
1) When the feeder switch 46, the vacuum switch 45, and the pump switch 44 are sequentially turned on by the operation of the operation panel 40 by the operator, the first to third relays 48 to 50 corresponding to the respective switches are turned on, and the feeder solenoid is turned on. , Vacuum valve 6 and vacuum pump 5 are turned on (step S2). When these three conditions are satisfied (meaning that each of the feeder solenoid, the vacuum valve 6, and the vacuum pump 5 is turned on; hereinafter, the time when these three conditions are satisfied is referred to as "paper feeding start"), the memory 51 is stored. The memory A area specified in advance is reset to "0" (step S3). At the same time, from this point of time, the CPU 41 adds the content of the area A of the memory by one each time the fall of the timing switch 43 (change from ON to OFF, see FIG. 5) is input (step S4). ). At 285 ° after seven rotations from 285 ° immediately after the start of paper feeding (at the time when the timing switch 43 falls), that is, when the area A of the memory becomes “8” (step S6), the input to the paper feeding sensor 18 Is confirmed (step S7). If the paper feed sensor 18 is turned on in this step S7 (step S7; ON), it means that the sheet has arrived at the front patch 16 in a normal conveyance state, and the process directly proceeds to the printing process ( Step S
8).

In step S7, if the paper feed sensor 18 is off, it means that the sheet 3 has not arrived at the front patch 16, and a paper jam has occurred at some point in the transport path. It should be. Therefore, in this case, the feeder solenoid is turned off by turning off the first relay 48 (step S9), and the separation / delivery section 1 and the transport section 11 are stopped. As a result, all mechanisms for transporting the sheet 3 to the front pad 16 are stopped, and thereafter, the stacked sheets 3 are not sent out from the stacking unit (the mounting table 2). Operation of the Modified Example In the above embodiment, the time from the start of sheet feeding to the arrival of the sheet 3 at the front pad 16 is measured by detecting the number of times of the fall of the timing switch 43 linked to the rotating member of the printing press. doing. On the other hand, there is a method of measuring time using a timer without using a timing switch. Hereinafter, this method will be described with reference to the flowchart shown in FIG. Note that the steps up to step S3 are the same as those in FIG. 4, and thus redundant description will be omitted, and steps after step S3 will be described.

Now, the time required for the printing machine to make one rotation is r seconds. As described above, when the sheet 3 is normally conveyed, it should arrive at the front patch 16 within 8 × r seconds from “start of sheet feeding”. Therefore, length 8 ×
If a timer for r seconds is configured, and the paper feed sensor 18 is turned on from “feed start” to the arrival at the front patch 16 (step S11; ON), it is determined that the sheet 3 has been normally conveyed. And the process proceeds to the printing process (step S1).
2). If 8 × r seconds or more have elapsed without the paper feed sensor 18 being turned on from the “paper feed start” to the arrival at the front pad 16 (step S13; YES), a paper feed jam occurs somewhere. Therefore, the feeder solenoid is turned off (step S14). Note that the timer is not configured by software, and the same control can be realized by using a timer relay.

[0021]

As described above, according to the present invention, if the sheet detecting unit does not detect a sheet even after a predetermined time has elapsed after the start of sheet feeding, the separating and sending unit is not required. And the transport unit are stopped, so that the subsequent sheet transport is not performed, so that the number of waste sheets can be reduced, and the jammed sheet is transported to the printing unit as a lump. There is no damage to the swing mechanism and surrounding mechanisms.

[Brief description of the drawings]

FIG. 1 is an overall side view of a mechanism system according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a printing section of the embodiment.

FIG. 3 is a block diagram of a control system of the embodiment.

FIG. 4 is an operation flowchart of the embodiment.

FIG. 5 is a time chart of the embodiment.

FIG. 6 is another operation flowchart of the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Separation sending part 2 ... Mounting table (lamination part) 3 ... Sheet paper 4 ... Suction foot 5 ... Vacuum pump 6 ... Vacuum valve 8 ... Front fence 12 ... Feeder board 16 ... Front patch 21 ... Printing part 41 ... CPU 41a ... Counting section 41b Stop control section 43. Timing switch 44. Pump switch 45. Vacuum switch 46. Feeder switch 48. First relay for controlling on / off of a feeder solenoid. 49. Second relay for controlling on / off of a vacuum valve. 50 3rd relay for turning on / off the vacuum pump

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41F 33/14 B41F 33/00

Claims (1)

(57) [Claims] 1. A separation / delivery unit for separating and sending out sheets stacked on a stacking unit one by one, and a conveyance for conveying the sheets separated and sent from the separation / delivery unit toward a printing cylinder. And a single sheet detecting unit disposed immediately before the printing cylinder and detecting the presence or absence of a sheet there, and starting separation of the sheet by the stacking unit. Thereafter, the elapsed time until a sheet arrives at the sheet detection unit is referred to as the single sheet
A time measurement unit that measures based on an output signal from the detection unit, the elapsed time measured by the time measurement unit,
After the separation of the sheets has started in the stacking section, the sheets are
The predetermined reference time required to arrive at the departure
When the elapsed time exceeds the reference time
And a stop control unit for controlling the separation and sending unit and the transport unit to stop. The apparatus for detecting a paper feed jam in a sheet-fed printing press, comprising: