JPH04347641A - Method of detecting improper paper feeding in sheet-feed press - Google Patents

Abstract

PURPOSE:To provide a method for detecting feeding of wrong paper sheets which makes it possible to reduce the wrong paper sheets to be supplied between printing cylinders of printing units to minimum. CONSTITUTION:There are provided wrong paper feeding detectors 24, 25, 26, 27, 28 which detect whether or not a wrong paper sheet is supplied and generated a detecting signal. When the wrong paper feeding detectors do not detect the wrong paper sheet feeding, printing is continued as the cylinders are set. If the detectors detect the wrong paper sheet feeding, all the printing cylinders of the printing units are simultaneously turned into the detached state, thereby stopping printing.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting incorrect paper feeding in a sheet-fed printing press, which detects when paper for printing is fed to a printing unit in an incorrect state.

0002

[Prior Art] In printing operations using a sheet-fed printing press, printing papers stacked on a paper stacking table of a paper feeding device are sucked one by one from the upper layer by a suction port of a suction device above the stacking table. The paper is sent forward, caught by rotating upper and lower paper feed rollers and paper feed rollers, and sent onto the feeder board. A plurality of paper feed belts running parallel to each other in the width direction of the paper run on this feeder board, and the paper is fed by the paper feed belt toward the feeder plate via the feeder board and a connecting plate following the feeder board. And, at the tip of the difference plate,
A front register device is provided to regulate the position of the paper in the vertical direction, and a transverse needle device is provided on the connecting plate, which together with the front register device constitute a register device and regulates the paper in the horizontal direction. . Paper registered for printing with such a registration device is
The paper is conveyed while being gripped by the claws of the swing device, and is fed from the swing device to the impression cylinder of the printing unit by changing the grip between the claws. Printing is then applied to this paper as it passes between the impression cylinder and the blanket cylinder.

[0003] At the tip of the difference plate, there is a so-called overshoot detector that detects when the conveyed paper has overcome the forehand of the forehand device that restricts its advance, and a so-called overshoot detector that detects when the conveyed paper has overcome the forehand of the forehand device that restricts its advance. There is a so-called double-sheet feed detector that detects when two sheets of paper are conveyed overlapping each other, and a so-called paper bend detector that detects when the front edge of the paper stops in a state that is not properly orthogonal to the paper conveyance direction. A detector such as a transverse needle device is provided, and a transverse needle detector is provided near the transverse needle device to detect whether or not lateral registration has been reliably performed. When these detectors detect the above-mentioned illegal paper feeding and issue a signal, they can stop the paper feeding by the paper feeding device or, for example, separate the blanket cylinder from the plate cylinder and the impression cylinder. Paper cutting is sometimes performed to stop the paper feeding.

0004

[Problems to be Solved by the Invention] However, in such a conventional paper feed detection device, even if the detector makes a normal detection, there is a delay in the unloading operation of the printing cylinder. Incorrect paper may be fed into the printing unit, resulting in the paper passing between the printing cylinders in an abnormal manner, applying excessive printing pressure and damaging the printing plate on the printing cylinder, or causing damage to the machine. This may result in an accident causing damage. This seems to be closely related to the fact that, in the case of a multicolor printing press, printing cylinders are removed in accordance with the arrangement order of printing units starting from the first color printing cylinder.

The present invention has been made in view of the above points, and provides a method for detecting incorrect paper feeding in a sheet-fed printing press, which makes it possible to minimize the amount of incorrect paper fed between printing cylinders. The purpose is to

[0006]

[Means for Solving the Problems] In order to achieve such an object, the present invention provides an unauthorized paper feeding detector that detects whether or not unauthorized paper feeding has occurred and issues a signal to detect the occurrence of unauthorized paper feeding. If the detector does not detect incorrect paper feeding, printing will continue with the cylinder inserted, and if this incorrect paper feeding detector detects incorrect paper feeding, the printing cylinders of all printing units will be removed at the same time and printing will stop. I tried to let them do it.

[0007]

[Operation] When paper feeding is started, a roll-in command is issued, roll-in is performed, and printing work is started. When printing is started or during printing, if there is no incorrect paper feeding, printing continues with the paper loaded. When an incorrect paper feed occurs and the incorrect paper feed detector detects this incorrect paper feed, the paper feed is stopped, and the cylinders of all printing units are simultaneously disengaged, and printing is stopped.

[0008]

[Embodiment] Figs. 1 to 4 are diagrams shown to explain the method of detecting incorrect paper feeding in a sheet-fed printing press according to the present invention, in which Fig. 1 is a side view of the vicinity of the insert plate, and Fig. 2 is a side view of the insert plate. 3 is a schematic side view of the four-color sheet-fed printing press, and FIG. 4 is a flowchart of the printing operation. In FIG. 3, the printing machine includes a paper feed device 1, four printing units 2, and a paper discharge device 3. It is being Each printing unit 2 also includes a plate cylinder 6 on which a plate is mounted on the circumference, an inking device and a water supply device (not shown) that supply ink and dampening water to the surface of the plate, and a rubber plate that is in contact with the plate cylinder 6. A cylinder 7 and an impression cylinder 8 facing the blanket cylinder 7 are provided. A transfer cylinder 9 is disposed facing each other between the impression cylinders 8 of the adjacent printing units 2, and the paper discharging device 3 is further provided with a paper discharging chain (not shown) and a paper discharging chain after printing. A paper stacking table 10 is provided for stacking paper 4 that is conveyed by a paper chain and then discharged. A feeder board 11, a difference plate 12, and a swing device 13, which will be described in detail later, are arranged between the paper feeding device 1 and the first color printing unit 2.

With this configuration, the papers 4 stacked on the paper stacking table 5 of the paper feeder 1 are sucked one by one by the suction port of the sucker device (not shown) provided above and transported. and the feeder board 11 is moved by the paper feed roller.
sent to the top. This paper is conveyed onto the differential plate 12 by a paper feed belt, and is supplied to the impression cylinder 8 by a swing device 13 and conveyed. At this time, since the image formed on the printing plate with the ink and dampening water is transferred to the blanket surface of the blanket cylinder 7, the paper 4 passing between the blanket cylinder 7 and the impression cylinder 8 is not exposed to the blanket cylinder. The image on 7 is transferred and printed. The paper 4 printed in the four colors in this manner is conveyed by a paper discharge chain (not shown) and falls onto the paper stacking table 10 to be stacked thereon.

[0010]The details of the difference plate 12 and the like will be explained with reference to FIGS. 1 and 2. In FIG. 1, 14 is the belt roller 1
A plurality of paper feed belts are attached to the feeder board 5 and stretched along the inclined feeder board 11, and convey the paper 4 pressed by the paper feed belt 14 with the presser rollers 16 etc. along the feeder board 11. The difference plate 12 formed in the shape of a long plate is connected to the feeder board 11.
The feeder board 11 is located in front of the feeder board 11 via the connecting plate 17.
It is supported at the same angle of inclination. A support plate 18 is supported between the left and right frames and supports the connecting plate 17 and the difference plate 12. Further, the swing device 13 is formed of a swing shaft 19 in which an axis of an outer periphery 19a supported by a bearing and an axis of an eccentric shaft 19b are eccentric, and a claw supported by the swing shaft 19 via an arm. As described above, the paper 4 that has stopped at the tip of the difference plate 12 is held in the grip by the claws, conveyed by the rotation of the arm, and then transferred to the claws of the impression cylinder 8. Furthermore, what is indicated by the reference numeral 20 in the figure is a differential plate 1.
A front support shaft (not shown) is fixed to the front support shaft 20, and the front support shaft 20 moves the paper 4 forward. In addition, when the paper 4 is conveyed by swinging, it is configured to be moved away from the tip of the difference plate 12 by rotation of the front shaft 20. Note that a register device is provided at the tip of the difference plate 12 to match the printing register in the vertical direction and the horizontal direction of the paper 4, but its illustration and explanation will be omitted.

The difference plate 12 is provided with various kinds of unauthorized paper feeding detection devices consisting of a light emitter and a light receiver, but in FIG. 2, the light receiver is omitted and only the light emitter is shown. Hereinafter, the projector will be referred to as a detector and will be given a reference numeral. First, above the difference plate 12, a light receiver support shaft 21 is supported between the left and right frames, and a holder 22 fixed to the light receiver support shaft 21 with a split clamp has a light receiver corresponding to each projector described below. A container 23 is attached. On the other hand, an overshoot detector 24 is fixed to the differential plate 12 by bolting it to the back surface of the differential plate 12 with its light emitting surface exposed. It is configured to issue an abnormal signal when the light beam is blocked by exceeding the pre-warning. Further, a two-sheet detector 25 is fixed to the difference plate 12 by bolting it to the back side of the difference plate 12 with its light emitting surface exposed, and the detectors 25 are fed one by one onto the difference plate 12. The apparatus is configured to detect a change in the light transmittance when two sheets of paper 4 are fed together, and to generate an abnormality signal. Furthermore, a pair of paper bending detectors 26 and 27 are fixed to the difference plate 12 by bolting them to the back surface of the difference plate 12 with their light emitting surfaces exposed. It is configured to detect that the leading edge of the paper 4 is stopped in a state where it is not properly orthogonal to the paper conveyance direction and to issue an abnormality signal. Furthermore, a body insertion detector 28 is fixed to the front end of the connecting plate 17, which detects when the paper 4 passes thereover and issues a body insertion signal. Further, on the connecting plate 17, a horizontal needle device 29 is located at the widthwise end of the connecting plate 17 to align the register of the paper 4 in the left-right direction by bringing the edge of the paper 4 fed into contact with the gauge. A horizontal needle detector (not shown) consisting of an emitter and a light receiver is provided near the horizontal needle device 29 to detect whether or not the horizontal needle device 29 is operating reliably. It is being

A method for detecting unauthorized paper feeding using the apparatus configured as described above will be explained with reference to the flowchart shown in FIG. Paper feeding device 1 is activated and printing work is started, and paper 4
When the paper is fed by the paper feeding tape 14 over the feeder board 11 onto the connecting plate 17, the front end thereof is detected by the body insertion detector 28, and a body insertion command is issued. Further, the paper 4 moves forward and stops because the advance is regulated by the preload. At this time, if the paper 4 is being fed correctly, each of the detectors 24, 25, 26, and 29 does not emit an abnormal signal, so the paper 4 is stopped. The paper 4 is supplied to the impression cylinder 8 by the swing device 13, and the printing operation is performed.

[0013] When the paper 4 exceeds the pre-loading position at the start of printing or during printing, and incorrect paper feeding occurs, the over-travel detector 24 detects this and stops the paper feeding operation, cancels the body insertion command,
Then, a command to deactivate all cylinders at once is issued, so the paper feeder 1 is stopped and the blanket cylinders 7 of all printing units 2 are
simultaneously separates from the plate cylinder 6 and the impression cylinder 8 and enters the disengaged state, stopping the printing operation. Also, when starting or during printing,
If two sheets of paper 4, which should be conveyed one by one, are conveyed overlapping each other, the double sheet feed detector 25 detects this and stops the sheet feeding operation, cancels the body insertion command, and Since a command to disengage all cylinders is issued one after another, the paper feeder 1 is stopped, and the blanket cylinders 7 of each printing unit 2 are sequentially separated from the plate cylinder 6 and impression cylinder 8 according to the arrangement order of the printing units 2 to be in the disengaged state. , and the printing operation stops. Furthermore, at the start of printing or during printing, the paper 4 fed onto the differential plate 12
If the leading edge of the paper stops in a state where it is not properly orthogonal to the paper transport direction, the paper bending detectors 26 and 27 detect this and stop the paper feeding operation, cancel the trunk loading command, and sequentially remove the entire trunk. Since the operation command is issued, the paper feeder 1 stops and the blanket cylinder 7 of each printing unit 2 is moved to the printing unit 2.
According to the arrangement order, the cylinders are successively separated from the plate cylinder 6 and the impression cylinder 8 to enter the disengaged state, and the printing operation is stopped. Furthermore, if the side edge of the paper 4 fed onto the connecting plate 17 passes through the horizontal stitching device 29 without being properly aligned with the horizontal stitching device 29 at the start of printing or during printing, The needle detector detects this and issues a command to stop the paper feeding operation, cancel the cylinder insertion command, and sequentially deactivate all cylinders, so the paper feeding device 1 stops and the blanket cylinders 7 of each printing unit 2 start printing. In accordance with the arrangement order of the units 2, they are successively separated from the plate cylinder 6 and the impression cylinder 8 to enter the disengaged state, and the printing operation is stopped.

[0014] In this embodiment, an example is shown in which all the cylinders are simultaneously released only when the overshoot detector 24, which is relatively prone to accidents, detects incorrect paper feeding, but the present invention is not limited to this. Instead, multiple types of incorrect paper feeding detectors 24
, 25, 26, 27, and 29 may be the target, or the effect will be greater if all the detectors are the target.

[0015]

[Effects of the Invention] As is clear from the above explanation, according to the present invention, as a method for detecting incorrect paper feeding in a sheet-fed printing machine,
A paper feed detector is installed that detects whether or not paper feed has occurred and issues a signal. By adopting a method in which when the paper feed detector detects incorrect paper feeding, the print cylinders of all printing units are removed simultaneously and printing is stopped, the unloading operation of the print cylinders is delayed and some incorrect paper feeds occur. Since the paper will not be fed to the printing unit, the paper may pass between the printing cylinders in an abnormal state and excessive printing pressure may be applied, damaging the printing plate on the printing cylinder or causing damage to the machine. There will be no damage or accidents, and the durability of printing plates and machines and work safety will be improved.

[Brief explanation of drawings]

FIG. 1 is a side view of the vicinity of a feed plate of a sheet-fed printing machine, shown for explaining a method for detecting incorrect paper feeding according to the present invention.

FIG. 2 is a plan view of the differential plate of the sheet-fed printing press.

FIG. 3 is a schematic side view of a four-color sheet-fed printing press.

FIG. 4 is a flowchart of the printing operation.

[Explanation of symbols]

1 Paper feeding device 2 Printing unit 6 Plate cylinder 7 Rubber body 8 Impression cylinder 12　　　　Different plate 23 Photo receiver 24 Overshoot detector 25 Two-sheet detector 26 Paper bending detector 27 Paper bend detector 28 Waist insertion detector

Claims (1)

[Claims] [Claim 1] An unauthorized paper feeding detector is provided which detects whether or not unauthorized paper feeding has occurred and issues a signal, and when the unauthorized paper feeding detector does not detect any unauthorized paper feeding, printing is performed while the paper is loaded. A method for detecting unauthorized paper feeding in a sheet-fed printing press, characterized in that when the unauthorized paper feeding detector detects unauthorized paper feeding, the printing cylinders of all printing units are simultaneously disengaged to stop printing.