JP3794790B2 - Control method of stencil printing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the structure of a stencil printing machine, and more particularly to the control of the operation of peeling the original plate from the plate cylinder.
[0002]
[Prior art]
A stencil printing machine is known in which an original plate that is perforated in accordance with the printing content is wound around a substantially cylindrical plate cylinder having ink permeability, and printing is performed on a printing medium such as paper with ink that has oozed out on the surface. ing. In this stencil printing machine, the used original plate is peeled off from the plate cylinder and sent to a box for collecting the discharged plate. A plurality of plate cylinders are provided for those that can be printed on both front and back sides, such as paper, and those that can be printed in multiple colors, and a plate removal mechanism is provided for peeling the used original plate for each plate cylinder. It has been.
[0003]
[Problems to be solved by the invention]
In a stencil printing machine equipped with a plurality of plate cylinders as described above, if a plurality of plate cylinders fail to be discharged and the original plate is clogged around the plate cylinder, the printing medium such as paper is transported when removing it. There is a problem that the route to be stained becomes dirty, and the print medium becomes dirty during the next printing operation.
[0004]
The present invention has been made to solve the above-described problem, and in a stencil printing machine having a plurality of plate cylinders, it facilitates the work when the original plate is jammed due to a failure of the plate removal operation, and the printing medium transport path It is an object of the present invention to provide a control method capable of processing the original plate without polluting.
[0005]
[Means for Solving the Problems]
In order to solve the above-described problem, the control method of the stencil printing machine according to the present invention is such that, in the plate removal, the plate removal of a plurality of plate cylinders is performed in order, and the plate discharges of the preceding and succeeding plate cylinders in the plate discharge order partially overlap. When the original plate is released from the plate cylinder that follows the plate cylinder that is adjacent in the sequence, the success or failure of the plate release in the adjacent plate cylinder in the sequence is judged. In addition, the original plate of the subsequent plate cylinder begins to be separated from the plate cylinder.
[0006]
According to this method, when the preceding plate cylinder fails to be discharged in the plate discharging operation, the subsequent plate cylinder is not discharged, so that the clogging of the original plate occurs only in one plate cylinder. Therefore, the jammed original plate needs to be processed only for one plate cylinder, and the operation is simplified. Therefore, the jammed original plate can be removed without contaminating the conveyance path of the printing medium such as paper.
[0007]
Further, even if the succeeding plate cylinder fails to be ejected, the operation can be continued until the preceding plate cylinder is ejected. According to this method, since the document jammed in the succeeding plate cylinder can be removed after completion of the plate removing operation of the preceding plate cylinder, workability is improved.
[0008]
Furthermore, the success or failure of the plate removal can be judged by the fact that the front end of the original plate has passed through a plate discharge roller that pinches and peels the original plate wound around the plate cylinder. The plate discharge roller rotates in synchronization with the rotation of the plate cylinder, holds the original plate, peels it off from the plate cylinder, and collects it. In most cases, the clogging of the original plate occurs because the front end of the original plate is not gripped by the discharge plate roller. Therefore, it is possible to determine whether or not the discharge operation is successful when the front end of the original plate passes through the discharge plate roller. .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings. FIG. 1 shows a schematic configuration of an apparatus for supplying and discharging a plate cylinder and an original plate of a stencil printing machine according to the present embodiment. This apparatus is provided with a substantially cylindrical plate cylinder 10 for surface printing and a plate cylinder 12 for back surface printing, on which a surface original plate 14 and a back surface original plate 16 are wound, respectively. Most of the cylindrical surfaces of the two plate cylinders 10 and 12 are formed of a porous material through which ink can permeate, and gripping mechanisms 18 and 20 for gripping the tips of the original plates 14 and 16 are arranged in part. ing. Further, the original plates 14 and 16 are perforated according to the printing contents. A transfer cylinder 22 is disposed in contact with each of the plate cylinders 10 and 12. The plate cylinders 10 and 12 and the transfer cylinder 22 are rotated by a drive mechanism (not shown) in the directions of arrows A, B, and C in the drawing and relatively so that there is no relative speed on the contact points of each other. The driving mechanism has one driving source and driving force transmitting means for transmitting the driving force from the driving source to the plate cylinders 10 and 12 and the transfer cylinder 22. The driving force transmitting means is constituted by a gear, a toothed belt, or the like that can keep the phase relationship between the plate cylinders 10 and 12 and the transfer cylinder 22 constant.
[0010]
The paper 24 as a print medium is conveyed from the paper feed tray 26 along the movement path 28 and sent to the paper discharge tray 30. The movement path 28 passes between the surface plate cylinder 10 and the transfer cylinder 22, and printing is performed in a portion between these. Plate-making parts 36 and 38 for forming the original plates 14 and 16 by punching the original film 32 and 34 based on the printing information are arranged at predetermined positions around the plate cylinders 10 and 12.
[0011]
Further, plate removal mechanisms 40 and 42 for collecting the original plates 14 and 16 that are no longer needed after printing is disposed at predetermined positions around the plate cylinders 10 and 12. The plate discharge guide claws 44 and 46 of the plate discharge mechanisms 40 and 42 peel the unnecessary original plates 14 and 16 from the plate cylinders 10 and 12 and guide them to the plate discharge rollers 48 and 50. 2 and 3, when the clamps 52 and 54 of the gripping mechanisms 18 and 20 are released, the plate cylinders 10 and 12 are lifted by the raising claws 60 and 61, respectively. It is further lifted to a position where it comes into contact with the discharge plate guide claws 44 and 46. 2 and 3 show a state in which the plate cylinders 10 and 12 and the transfer cylinder 22 are rotated by a predetermined angle from the state shown in FIG. 1, and the same reference numerals as those in FIG. Description is omitted. The plate discharge rollers 48 and 50 are constituted by two rollers, and the guided original plates 14 and 16 are sandwiched between the two rollers and sent to the plate discharge collection boxes 56 and 58. Further, immediately after the plate discharge rollers 48 and 50, plate discharge sensors 62 and 64 are arranged. The plate ejection sensor 62 includes a light emitting unit and a light receiving unit that receives light from the light emitting unit, and detects whether there is an original in the optical path based on the presence or absence of light reception. In the plate discharging operation, the most frequent error is that the original plates 14 and 16 are not guided well to the plate discharging rollers 48 and 50 and are jammed around the plate discharging mechanisms 40 and 42. On the other hand, if the leading ends of the original plates 14 and 16 are successfully guided to the discharge plate rollers 48 and 50 and sent backward by the two rollers, then the original plates 14 and 16 are sequentially transferred by the rotation of the discharge plate rollers 48 and 50. It is peeled off from the cylinders 10 and 12 and collected in the discharged-plate collection boxes 56 and 58. Therefore, if the original plates 14 and 16 reach the rear of the plate discharge rollers 48 and 50, it is very unlikely that an error related to the plate discharge operation will occur thereafter, and the success or failure of the plate discharge operation can be determined based on this. .
[0012]
The printing operation is performed as follows. The original film 32, 34 wound on the reel before punching is punched in accordance with the printing contents in the plate making sections 36, 38 and sent to the surface of the plate cylinders 10, 12. Here, the tips of the original plates 14 and 16 are held by the clamps 44 and 46 of the holding mechanisms 18 and 20, and the original plates 14 and 16 are wound around the surfaces of the plate cylinders 10 and 12 as the plate cylinders 10 and 12 rotate. An ink supply mechanism (not shown) is arranged inside the plate cylinders 10 and 12, and ink supplied from the ink passes through the porous portions of the plate cylinders 10 and 12 and the holes of the original plates 14 and 16. , 16 ooze out on the surface. The ink that has oozed out on the surface of the front plate cylinder 10 is transferred to the surface of the paper 24 that has been conveyed at a predetermined timing on the movement path at the transfer position P _A that is the contact point between the plate cylinder 10 and the transfer cylinder 22. Is done. On the other hand, the ink that has oozed out on the surface of the back plate cylinder 12 is once transferred to the surface of the transfer cylinder 22 at a transfer position P _B that is a contact point between the plate cylinder 12 and the transfer cylinder 22. Transferred ink in accordance with the rotation of the transfer cylinder 22, are transported to the transfer position P _A, where it is transferred back to the back surface of the paper 24. Thus, the transfer cylinder 22 functions as an intermediate print medium, and the movement path of the surface of the transfer cylinder 22 is the movement path of the print medium. Therefore, the plate cylinder 10 located on the upstream side of the movement path is the plate cylinder 10 for the front surface, and the plate cylinder 12 for the back surface is located downstream. Printing is performed on both sides of one sheet 24 by the transfer by the plate cylinder 10 for the surface and the transfer by the transfer cylinder 22, and the sheet 24 is discharged to the discharge tray 30.
[0013]
When printing of a predetermined number of sheets is completed, the clamps 52 and 54 are opened at the positions of the plate release mechanisms 40 and 42, and the leading ends of the original plates 14 and 16 abut against the plate release guide claws 44 and 46. The positions on the plate cylinders 10 and 12 facing the tips of the plate discharge guide claws 44 and 46 at this time are plate discharge positions E _A and E _B. The original plates 10 and 12 that are in contact with the plate discharge guide claws 44 and 46 are collected by the plate discharge rollers 48 and 50 into the plate release boxes 56 and 58.
[0014]
Next, the plate discharging operation of this embodiment will be described in more detail. 4 and 5 show control flowcharts related to the plate removal operation. When the predetermined printing is finished, the plate removal operation is started. First, a position where the rotation axis of the clamp 52 of the surface plate cylinder 10 (hereinafter, the position of this rotation axis is referred to as a reference position of the plate cylinder 10) faces the tip of the plate discharge guide claw 44 (plate release position E). _The plate cylinder 10 is rotated until it reaches ( _A ), and is stopped when reaching this point (S100). This state is the state shown in FIG. Here, the clamp 52 is released (S102), and the tip of the original plate 14 is lifted from the plate cylinder by the raising claw 60 (see FIG. 2). Next, the plate ejection guide claw 44 is moved from the position of the broken line shown in FIG. 1 to the position of the solid line (S104) so that the leading end of the original 12 is easily brought into contact. Further, rotation of the plate discharge roller 48 is started (S106), and rotation of the plate cylinder 10 is started (S108).
[0015]
The plate cylinders 10 and 12 rotate at the same time as described above, and the rotation axis of the clamp 54 of the plate cylinder 12 for the back surface (hereinafter, the position of this rotation axis is referred to as the reference position of the plate cylinder 12) is discharged. The plate cylinders 10 and 12 are rotated until they reach a position facing the tip of the guide claw 46 (plate removal position E _B ). Then, when the reference position of the plate cylinder 12 becomes discharged printing plate position E _B (S110), stencil discharging rollers 48 to stop rotation of the plate cylinder 10, 12 (S112). This state is shown in FIG. Then, in the current plate discharging operation, it is determined whether the original plate 14 on the plate cylinder 10 is a target for discharging (S114). If the original plate 14 is a target for discharging, whether the plate discharging sensor 62 is on (S116), that is, It is determined whether the original 14 exists at the position of the plate removal sensor 62. If the original plate 14 is not detected at this time, it is determined that the original plate 14 is not normally discharged, and an error warning is issued to stop the discharging operation (S118). On the other hand, if it is determined in step S114 that the original plate 14 is not the target for discharging, and if the original plate 14 is detected by the discharging plate sensor 62 in step S116, it can be determined that the normal operation is being performed, and the discharging is performed. Continue operation.
[0016]
Since the reference position of the plate cylinder 12 for the back surface has reached the plate discharge position E _B from step S110, the clamp 54 is released, and the leading end of the original plate 16 is lifted from the plate cylinder 12 (S120). Further, the plate discharge guide claw 46 is moved from the position of the broken line in FIG. 1 to the position of the solid line (S122) so that the front end of the original plate 16 can easily come into contact. Further, the discharge roller 50 is rotated (S124). Then, rotation of the plate cylinders 10 and 12 and the surface discharge roller 48 is started (S126). Plate cylinder 10 it at the reference position again stencil discharging position E _A of for surface (S128), the plate cylinder 12 it is determined whether the a plate discharge interest in this plate discharge operation (S130). If the target is to be discharged, it is further determined whether the discharged plate sensor 64 is on (S132). If it is not on, an error warning is given and the discharged plate operation is stopped (S134). In step S128, the fact that the reference position of the plate cylinder 10 is in the plate discharge position E _A again, that actually will be the plate cylinder 10 from the plate discharge is initiated in the original 14 is round, the plate cylinder for surface For 10, the plate removal operation is completed. At this time, it is determined whether the plate removal operation related to the back plate cylinder 12 is normally performed. If it is not normally operated, an error warning is given at this time, and the operation is stopped. By doing in this way, it is possible to first terminate the plate discharging operation relating to the preceding surface plate cylinder 10 that has already been determined to be operating normally. Even if an abnormality occurs with respect to the subsequent plate cylinder 12 for the back surface, since the plate removing operation of the preceding plate cylinder 10 has already been completed, it is easy to remove the jammed original plate. On the other hand, if the plate cylinder 12 is not a target for discharging in step S130, or if the discharging sensor 64 is turned on in step S132, the discharging operation is continued.
[0017]
First, the surface discharge roller 48 for which the plate has already been discharged is stopped (S134), and the plate discharge guide claw 44 is retracted to the position of the broken line in the drawing (S136). At the same time, the plate cylinders 10 and 12 are continuously rotated (S138), and it is determined whether the reference position of the plate cylinder 12 has reached the plate discharge position E _B (S140). That is, with respect to the plate cylinder 12, after the plate is actually discharged, it is determined whether the plate cylinder 12 has rotated once and the plate has been discharged. If it is determined that the plate removal is completed, the rotation of the plate discharge roller 50 is stopped (S142), and the plate discharge guide claw 46 is retracted to the position of the broken line in the drawing (S144). Then, the rotation of the plate cylinders 10 and 12 is stopped.
[0018]
Since the two plate cylinders 10 and 12 and the transfer cylinder 22 rotate at the same speed so as not to be relatively displaced, in order to shift the plate discharging operations of the two plate cylinders 10 and 12 in this embodiment, Then, this is realized by appropriately determining the discharge positions E _A and E _B. For the following explanation, the discharge positions E _A and E _B are defined as follows. The plate discharge position E _A of the plate cylinder 10 for surface, defined by the arc length C _A measured from the transfer position P _A in the direction of rotation of the plate cylinder 10. Further, the plate removal position E _B related to the back surface is defined by an arc length C _B measured from the transfer position P _{B in} the rotation direction of the plate cylinder 12. These arc length C _A, C _B, in turn, transfer position P _A, plate discharge position from the P _B E _A, road C _A along the surface of the plate cylinder 10, 12 to E _B, of C _B that Is also possible. Furthermore, the distance from the transfer position P _A to the transfer position P _B along the rotation direction of the transfer cylinder 22 as an intermediate print medium is m. Further, it is assumed that a virtual plate removal position E _C with respect to the plate cylinder 12 where the plate discharge operations of the two plate cylinders 10 and 12 are performed simultaneously. The position of the plate removal position E _C is defined by the arc length C _C measured from the transfer position P _{B in} the rotation direction of the plate cylinder 12. At this time, the road C _C can be expressed by the following equation.
[0019]
[Expression 1]
C _C = C _A −m (1)
Therefore, in order to delay the plate removal operation of the plate cylinder 12 from the plate cylinder 10, the plate discharge position E _B of the back plate cylinder 12 may be provided at a position further advanced by α than the virtual plate discharge position E _C. . Therefore, road C _B can be expressed by the following equation.
[0020]
[Expression 2]
C _B = C _C + α
= C _A -m + α (2)
In Formula (1), when the road C _C is negative, the position measured by the road C _C from the transfer position P _{B in the} direction opposite to the rotation direction of the plate cylinder 12 is the virtual plate discharge position E _C. . The value of α is set by taking into account a margin for reliably determining the arrangement of other components of the apparatus and the success or failure of the plate removal operation of the preceding plate cylinder.
[0021]
As described above, in the case of the present embodiment, the plate discharging operation of the two plate cylinders 19 and 12 is shifted, and the plate discharging operation of the subsequent plate cylinder 12 is started only when the plate discharging operation of the preceding plate cylinder 10 is successful. . By doing in this way, it is prevented that both the original plates 14 and 16 of the two plate cylinders 10 and 12 become clogged, and the removal operation of the jammed original is made easy. When both of the front and back original plates 14 and 16 are jammed, the plate cylinders 10 and 12 try to rotate in synchronization with each other, so that the components on the conveyance path 28 are soiled with the other original paper during one removal operation. This part also has to be cleaned, which increases the labor of the work.
[0022]
Further, by performing success / failure of the succeeding plate cylinder after the preceding plate cylinder has been ejected, the ejecting operation is continued until the preceding plate cylinder has been ejected. As a result, it is not necessary to perform the operation of removing the original plate of the succeeding plate cylinder in a state where the original plate remains in the preceding plate cylinder, and the operation is facilitated.
[0023]
FIG. 6 shows another embodiment according to the present invention. In this figure, the same components as those of the embodiment shown in FIG. What is characteristic in the present embodiment is that, with regard to printing on the back surface, the ink is directly transferred by the plate cylinder 12 for the back surface without using the transfer cylinder. Therefore, instead of the transfer cylinder 22, pressure cylinders 66 and 68 that sandwich the sheet 24 together with the plate cylinder are arranged facing the plate cylinders 10 and 12. Therefore, in the present embodiment, the transfer positions P _A and P _B are points where the plate cylinders 10 and 12 and the impression cylinders 66 and 68 contact each other. In addition, the movement path of the print medium passing through the transfer positions P _A and P _B is the path of the sheet 24 being conveyed. If the distance along the path is m as in the above-described embodiment, the expression ( According to 2), the position of the plate removal with respect to the back plate cylinder 12 can be determined. As for the positive and negative values of C _C calculated by Expression (1), as in the above-described embodiment, if the value of C _C is positive, the transfer position P _B measured along the rotation direction of the plate cylinder 12 is used. The arc length to the virtual plate removal position E _C is represented, and if it is negative, the arc length measured in the reverse direction of the rotation direction is represented. The control is exactly the same as in the previous embodiment.
[0024]
In particular, in the present embodiment, the plate discharge positions E _A and E _B are determined so that the conveyance path 28 is not soiled by the original plate 16 of the plate cylinder 12 even if the subsequent plate cylinder 12 has failed to be discharged. FIG. 7 shows a state where the succeeding plate cylinder 12 has failed to be discharged and the leading edge of the original plate 16 has not been guided to the discharge roller 50. Thereafter, when the plate cylinders 10 and 12 are rotated by an angle β, the plate removal of the preceding plate cylinder 10 is completed. On the other hand, the leading end of the original plate 16 of the subsequent plate cylinder 12 has not yet reached the transport path 28. At this time, if the original plate 16 that has failed in the plate removal is removed, it is only necessary to remove the original plate 16 from the subsequent plate cylinder 12, and the operation is simplified.
[0025]
FIG. 8 shows still another embodiment according to the present invention. In this figure, the same components as those in the embodiment shown in FIG. 1 and the like are denoted by the same reference numerals, and the description thereof is omitted. In this embodiment, the sheet 24 is sandwiched between the front plate cylinder 10 and the back plate cylinder 12 and the ink is transferred at the same position. In this case, the gripping mechanisms 18 and 20 are arranged at positions slightly recessed from the cylindrical surfaces of the plate cylinders 10 and 12. This is to prevent the gripping mechanisms 18 and 20 from interfering with each other when they come to the opposing positions. Since this embodiment can be seen in the embodiment shown in FIG. 6 in which the path m between the transfer positions is 0, from the equation (2),
[Equation 3]
C _B = C _A + α (3)
Is obtained.
[0026]
In particular, in the present embodiment, the plate discharge positions E _A and E _B are determined so that the conveyance path 28 is not soiled by the original plate 16 of the plate cylinder 12 even if the subsequent plate cylinder 12 has failed to be discharged. FIG. 9 shows a state where the succeeding plate cylinder 12 has failed to be discharged and the leading end of the original plate 16 has not been guided to the discharge roller 50. Thereafter, when the plate cylinders 10 and 12 are rotated by an angle β, the plate removal of the preceding plate cylinder 10 is completed. On the other hand, the leading end of the original plate 16 of the subsequent plate cylinder 12 has not yet reached the transport path 28. At this time, if the original plate 16 that has failed in the plate removal is removed, it is only necessary to remove the original plate 16 from the subsequent plate cylinder 12, and the operation is simplified.
[0027]
According to each of the above embodiments, when removing the jammed original plate, the other master plate is not in the middle of the plate discharging operation or clogged, so that the removal operation is facilitated. Further, in the case of this embodiment, the control is performed so that the plate removing operation for one plate cylinder is completed after the plate removing operation for the other plate cylinder is finished so that the two plates are not clogged at the same time. In this case, since the two plate cylinders partially overlap each other, the time required for the entire plate removal operation is short.
[0028]
Further, in each of the above embodiments, the success or failure of the plate removal is determined based on the fact that the original plate exists immediately after the plate discharge roller. What is necessary is just to judge success or failure at a stage. For example, it is possible to make a determination based on whether the original plate has passed through the discharge plate guide claw.
[0029]
In each of the above-described embodiments, the apparatus having two plate cylinders has been described. However, the present invention can also be applied to an apparatus having three or more plate cylinders. That is, by shifting the plate discharging operation of each plate cylinder little by little, it is possible to prevent a plurality of plate cylinders from causing errors in the plate discharging operation at the same time.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of an apparatus according to an embodiment of the present invention.
FIG. 2 is a view for explaining a plate removal operation of the apparatus of FIG. 1;
FIG. 3 is a diagram for explaining a plate removal operation of the apparatus of FIG. 1;
FIG. 4 is a flowchart showing a flow of control related to a plate removal operation of the apparatus of FIG. 1;
FIG. 5 is a flowchart showing a flow of control relating to the plate removal operation of the apparatus of FIG. 1;
FIG. 6 is a diagram showing a schematic configuration of an apparatus according to another embodiment of the present invention.
FIG. 7 is a view for explaining a plate removal operation of the apparatus of FIG. 6;
FIG. 8 is a diagram showing a schematic configuration of an apparatus according to still another embodiment of the present invention.
FIG. 9 is a diagram for explaining a plate removal operation of the apparatus of FIG. 8;
[Explanation of symbols]
10, 12 plate cylinder, 14, 16 original plate, 18, 20 gripping mechanism, 22 transfer cylinder, 24 paper (print medium), 28 movement path, 40, 42 plate removal mechanism, 44, 46 plate removal guide claw, 62, 64 plate removal sensor , P _A , P _B transfer position, E _A , E _B discharge position.

Claims (3)

A plurality of plate cylinders around which the original plate with predetermined perforations is wound are provided, the plate cylinders are rotated and brought into contact with the printing medium, the ink exuded from the perforations of the original plate is transferred to the printing medium, and the printing is finished said plate by plate discharging device provided for each plate cylinder while the cylinder is rotating plate discharge by the peeling of the master from the plate cylinder, a control method of the stencil printing machine,
A plurality of plate cylinders are discharged in sequence, and the adjacent plate cylinders adjacent to each other in this discharge order are partially overlapped, and the original plates of the subsequent plate cylinders in the adjacent plate cylinders in the order are removed from this plate cylinder. At the time of starting separation, the succession of succession of the preceding plate cylinder of the adjacent plate cylinders in the sequence is judged, and if this plate removal is successful, the master of the subsequent plate cylinder starts to be separated from this plate cylinder. Control method of printing press. A method of controlling a stencil printing machine according to claim 1, even if the plate discharge of the subsequent plate cylinder fails, to the plate discharging of the plate cylinder of the preceding ends continues the plate discharge operation, the stencil printing machine Control method. 3. The stencil printing machine according to claim 1, wherein the success of the stencil printing is determined by the fact that the leading edge of the stencil has passed through a stencil roller that pinches and peels the stencil wrapped around the stencil cylinder. Control method.

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