JPH0137272B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet-fed gravure rotary printing machine that can also be used as a coating machine for forming a coating film of synthetic resin or the like on a paper surface.

In gravure printing, a photolithographic plate is mounted on a plate cylinder, and ink is supplied to the concave surface of the plate by a roller.
Printing is performed by applying pressure to the paper that passes between the plate cylinder and the impression cylinder, and the method of supplying ink to the plate surface is by using a roller immersed in ink in an ink tank. A method is used in which ink is supplied to the entire surface of the plate, and then the ink is scraped off from areas other than the concave portions, which are the image areas, using a doctor.

This type of gravure printing is often used for high-volume printing that requires plate durability, or for printing that takes advantage of the good gradation characteristics unique to gravure printing, but the platemaking cost is high, and it is not suitable for general-purpose printing. Due to some aspects such as lack of performance, machines rarely operate at full capacity, and there is a need to expand the scope of their application and improve operating rates.

The present invention has been made in response to such demands, and includes a main doctor that faces the entire width of the plate and a pair of auxiliary doctors that touch each end of the plate on both sides, each of which is connected to the plate by a support on the machine body. After the coating material instead of ink is supplied to the entire flat plate mounted on the plate cylinder using a coating roller, the main doctor, which is attached to and removed from the plate by a cam drive, coats the edge of the paper. Scrape off excess coating material and use the auxiliary doctor to scrape off the coating material on both ends of the plate. By making the cam's action range and the auxiliary doctor's action range freely adjustable, it can be used for coating paper surfaces of various sizes. We provide a sheet-fed gravure rotary printing press that makes it possible to do this. Embodiments of the present invention will be described in detail below with reference to the drawings.

1 to 4 show an embodiment of a sheet-fed rotogravure rotary printing press according to the present invention, in which FIG. 1 is a schematic side view, FIG. 2 is an expanded vertical sectional view of the vicinity of the plate cylinder, and FIG.
The figure is a side view from A in Fig. 2, and Fig. 4 is the BB side view in Fig. 2.
FIG. In the figure, a printing machine 1 includes a paper feeding device 2, a printing device 3, and a paper ejecting device 4. Paper 5 is loaded on the paper feeding device 2, and each time a predetermined number of sheets are fed out, the printing machine 1 automatically It is equipped with a paper stacking table 6 that rises. The printing device 3 also includes a plate cylinder 7, which will be described in detail later, an impression cylinder 10 which is in contact with the plate cylinder 7 and is equipped with a claw that receives the sheets of paper 5 sent one by one onto the differential plate 8 via a swing 9. A paper take-up cylinder 11 is provided which faces the impression cylinder 10. A sprocket 12 coaxial with the paper take-up cylinder 11 and a sprocket 1 of the paper discharge device 4
A paper ejecting chain 14 is stretched between the paper ejecting cylinder 14 and the paper ejecting chain 14, and the paper ejecting chain 14 receives the paper 5 held in its claws and wound around the impression cylinder 10 in cooperation with the paper taking cylinder 11. A plurality of sets of gripping claws each having a claw and a claw base for receiving and conveying the sheet to the discharge device 4 as the chain 14 runs are arranged at regular intervals. Further, the paper ejecting device 4 is provided with a paper stacking table 15 on which the paper 5 that is released from the claw and falls at the end of the conveyance is stacked.

The plate cylinder 7 is pivotally supported by left and right frames 17 via bearings 16, and a plate 18 is wound around the circumferential surface of the plate cylinder 7, both ends of which are held in a plate vise in an outer peripheral notch. This version 18 has an arrow C in the figure.
The leading side in the direction of rotation of the plate cylinder 7 shown by is called the gripping side, and the trailing side is called the trailing side. An ink tank 20 storing printing ink 19 or vinyl resin for coating (hereinafter referred to as ink in the description of the structure) is supported diagonally below the plate cylinder 7 between the frames 17 on both sides.
An inking roller 21, which is driven to rotate with its circumferential surface in contact with the plate 18, is mounted therein, with approximately 1/3 of its circumferential surface immersed in ink 19. Note that this ink forming roller 21 is attached to the plate 1 by a mechanism not shown.
The contact pressure with 8 can be adjusted.

A freely rotatable doctor shaft 22 and an auxiliary doctor shaft 23 whose rotation is restricted by a key or the like are installed on the downstream side of the ink forming roller 21 in the direction of rotation of the plate cylinder 7, and are arranged vertically near the plate cylinder 7. A shaft is mounted between the frames 17 on both sides, and the doctor shaft 22 has a plate cylinder 7.
A doctor stand 24 serving as a support for the doctor, which is slightly longer than the entire length of the doctor table, is fitted and fixed. This doctor stand 2
4, three upper and lower doctor holding plates 26, 27, 28 having elongated holes 25 are fixed with bolts 29, and these doctor holding plates 26, 2
A main doctor 30 and a restraining plate 31 are held between 7 and 28. Among these, the main doctor 30 is
It is made of plate material and is slightly longer than the entire length of the plate cylinder 7, and its tip is brought into contact with the plate 18. Also, the holding plate 31 is formed to have the same length as the main doctor 30, and suppresses the main doctor 30 and makes it elastic. keeping. Reference numeral 32 denotes a plurality of adjustment screws screwed into the doctor table 24 in parallel. By slightly loosening the bolt 29 and rotating the adjustment screw 32, the main doctor 30 can be adjusted to the doctor holding plates 26, 2.
The contact pressure of the main doctor 30 against the plate 18 is adjusted by moving forward and backward together with the main doctor 7 and 28.

On the other hand, a cam base 34 fixed to an end shaft 33 of the plate cylinder 7 protruding from the frame 17 has a doctor attachment/detachment cam 35 having a cam surface on the outer periphery attached to a plurality of bolts 3.
6, and this doctor attachment/detachment cam 35 is fixed to a disc-shaped master cam 37 and its fan-shaped notch by engagement of a long hole 38 and a bolt 39. It is formed with a fan-shaped cam piece 40. And both cam surfaces 37, 40
are the large diameter portions 37a, 40a and the small diameter portion 37, respectively.
By loosening the bolt 39 and moving the cam piece 40 in the circumferential direction, the small diameter part 37b and the large diameter part 40a can be separated.
The small diameter portion of the entire cam 35 is configured to be expanded or contracted by changing the overlapping angle with the cam 35. On the other hand,
A cam lever 41 is fixed to the protruding end of the doctor shaft 22 from the frame 17 with a bolt 42, and a cam follower 43 that is in contact with the cam surface of the doctor attachment/detachment cam 35 is pivotally attached to the free end of the cam lever 41. There is. Further, a bracket 44 is fixed to the frame 17, and a spring shaft 47 that connects a stud 45 rotatably pivoted to the bracket 44 and a stud 46 on the cam lever 41 side includes:
A compression coil spring 48 that applies a rotational force to the cam lever 41 in the direction of pressing the cam follower 43 against the cam surface is attached so that its elastic force can be freely adjusted. Reference numeral 49 denotes a handle fixed to the doctor shaft 22 with a bolt 50 adjacent to the frame 17. By selectively rotating this handle to the positions shown by the solid line and the chain line in FIG. 3, the doctor shaft 22 can be moved. The integrated cam lever 41 is rotated through the cam lever 41, and is configured to move beyond the dead center due to the elastic force of the compression coil spring 48 and occupy the positions shown by the solid line and the chain line in FIG. 3, respectively. Further, on the frame 17 side, freely adjustable stoppers 51 and 52 are provided, respectively, to restrict the rotation of the cam lever 41 at both limit positions.

An auxiliary doctor stand 53 serving as a support for the auxiliary doctor, which is slightly longer than the entire length of the plate cylinder 7, is fitted and fixed on the auxiliary doctor shaft 23, and on its upper surface,
two upper and lower doctor holding plates 55 each having a long hole 54;
56 is fixed by a lock handle 57, and on these doctor holding plates 55, 56, a pair of left and right auxiliary doctors 58 formed narrowly from plate material are attached.
is being held. These pair of auxiliary doctors 58
are held with their tips facing both ends of the plate 18 in the width direction, and can be freely adjusted to move in the width direction according to the paper size by slightly loosening the lock handle 57. By rotating and moving the blade 18 forward and backward, it moves forward and backward together with the doctor holding plates 55 and 56, and the contact pressure against the plate 18 is adjusted.

The operation of the sheet-fed rotogravure rotary printing press configured as described above will be described with respect to the case where it is used for gravure printing and the case where it is used for coating. First, in the case of gravure printing, bolt 3
6 and remove the entire doctor attachment/detachment cam 35 from the cam base 34.
After removing the cam lever 41 from the stopper 5,
1, the contact pressure of the main doctor 30 against the plate 18, which is an intaglio plate for gravure printing, is adjusted by an adjusting screw 32. In addition, the auxiliary doctor 5
8 is removed or removed from the plate 18 to be in an unused state, and the ink tank 20 stores ink 19 for printing. When the machine is prepared and operated in this manner, the plate cylinder 7 and the ink forming roller 21 rotate, and the ink 19 in the ink tank 20 is transferred to the ink forming roller 21 and supplied to the entire surface of the plate 18, and then sent to the main doctor. 30, and the ink 19 is left on the plate 18 only in the concave portions where the image is formed. Then, when the paper 5 on the paper stacking table 6 is fed onto the differential plate 8 and transferred from the swing 9 to the claw of the impression cylinder 10, it is wrapped around the impression cylinder 10 and conveyed. The ink 19 in the concave portions of the plate 18 is transferred and gravure printing is performed. The printed paper 5 is conveyed by a paper discharge chain 14 via a paper take-up cylinder 11, drops at the end of the conveyance, and is stacked on a paper stacking table 15.

Next, when coating work is to be performed using this printing press, a plate for coating is mounted on the plate cylinder 7. This plate is generally a plated iron or copper plate about 0.7 mm thick, and its size is constant regardless of the paper size. and,
A coating material such as vinyl chloride resin liquid is put into the ink tank 20, and the plate 1 is adjusted by an adjustment screw (not shown).
The thickness of the coating film is adjusted by adjusting the contact pressure of the inking roller 21 with respect to the inking roller 8. Next, the doctor attachment/detachment cam 35 is attached to the cam stand 34 and fixed with bolts 36, and each of the pair of left and right auxiliary doctors 5 is
The tips of the plates 8 and 8 are brought into contact with both ends of the plate 18, respectively, and the contact pressure is adjusted using adjustment bolts 59. After preparing in this way, when the printed paper 5 to be coated is loaded onto the paper stacking table 6 and the machine is operated, the paper 5 is transferred to the impression cylinder 1 as in the case of gravure printing.
0 and the plate cylinder 7. On the other hand, after the coating material 19 in the ink tank 20 is supplied to the entire surface of the plate 18, the main doctor 30 and the auxiliary doctor 58
scraped off by In this case, due to the rotation of the doctor attachment/detachment cam 35, the small diameter portions 37a, 40a
While the cam follower 43 is in contact with the main doctor 30 via the cam lever 41 and the doctor shaft 22,
is in contact with the plate 18 and scraping is performed. Further, while the cam follower 43 is in contact with the large diameter portions 37b and 40b, the main doctor 30 is separated from the plate 18 and scraping is stopped. i.e. version 1
The length of paper 5 in the circumferential direction is constant, while paper 5
The vertical size of the paper generally changes in the range of 350 mm to 632 mm, and this is changed on the paper tail side, so if you adjust it by moving the cam piece 40 in the circumferential direction according to the paper size, The angle of the small diameter portions 37b, 40b is expanded or contracted, and the scraping operation angle during one rotation of the plate cylinder 7 changes in accordance with the paper size. Further, the auxiliary doctor 58 has the plate 18
Scraping is performed over the entire circumference in the circumferential direction of the plate 18, but in the width direction of the plate 18, only both ends are scraped off. This can be handled by loosening the lock handle 57 and moving the auxiliary doctor 58. Also
For paper with a narrow width of about 500 mm, use the auxiliary doctor 58.
You can replace it with a wider one. By adjusting in this way, the surface of the plate 18 has the following properties:
The coating material 19 remains in an area corresponding to the area from the gripping side of the paper 5 to 3 to 5 mm before the end of the paper and corresponding to the entire width of the paper, and the coating material 19 in other parts is scraped off. Therefore, as described above, when the paper 5 passes between the impression cylinder 10 and the plate cylinder 7, the coating is applied to the inner side of the paper 5 by 3 to 5 mm to cover almost the entire surface of the paper. And in this case, 4 laps of paper 5 3~
The coating material 19 adhering to the plate surface at a width of 5 mm and away from the paper 5 is all scraped off.
Even if the impression cylinder 10 is brought into contact with the impression cylinder 10, the so-called cylinder printing state in which the coating material 19 is transferred to a portion of the impression cylinder 10 where there is no paper 5 will not occur, and the coating material will not wrap around the back side of the paper 5 or Materials will not fly away during operation.

Furthermore, when the main doctor 30 is not in use, such as when replacing the plate 18, the camray 41 is stopped by the elastic force of the compression coil spring 48 by grasping the handle 49 and rotating it to the chain line position in FIG. The main doctor 30 rotates to the chain line position while passing the point, and the rotation is restricted by contacting the stopper 52, so that the main doctor 30 can be detached from the plate 18 in a stable state in which it is supported by the compression coil spring 48.

As is clear from the above description, according to the present invention, in a sheet-fed gravure rotary printing press, a main doctor facing the entire width of the plate and a pair of auxiliary doctors facing each end of both sides of the plate are placed on the machine body side. The contact pressure with the plate is supported by a support that allows adjustment of the contact pressure with the plate, and a coating material instead of ink is supplied to the entire flat plate attached to the plate cylinder by a coating roller, and then the plate is attached to and removed from the plate by a cam drive. The main doctor scrapes off the excess coating material on the edge of the paper, and the auxiliary doctor scrapes off the coating material on both sides of the plate. By configuring the cam's action range and the auxiliary doctor's action range to be freely adjustable, the printing machine In addition to being able to perform high-performance gravure printing, which is used for The range of applications for this system is expanded, the annual operating rate is improved, and production costs can be reduced.

[Brief explanation of drawings]

1 to 4 show an embodiment of a sheet-fed rotogravure rotary printing press according to the present invention, in which FIG. 1 is a schematic side view, FIG. 2 is an expanded vertical sectional view of the vicinity of the plate cylinder, and FIG.
The figure is a side view from A in Fig. 2, and Fig. 4 is the BB side view in Fig. 2.
FIG. 1... Printing machine, 7... Plate cylinder, 18... Plate, 21
...Ink forming roller, 24...Doctor stand, 30...
...Main doctor, 32...Adjustment screw, 35...Doctor attachment/detachment cam, 53...Auxiliary doctor stand, 57...
Lock handle, 58... Auxiliary doctor, 59...
Adjustment screw.

Claims (1)

[Claims] 1. A plate cylinder on which a plate is mounted on its circumferential surface, an ink forming roller that is rotationally driven in contact with the plate surface of this plate cylinder,
A main doctor whose tip is in contact with almost the entire width of the plate and is supported by a support on the machine body so as to be able to move forward and backward in the direction of contact pressure with the plate; A doctor attachment/detachment cam having a cam surface formed to be able to adjust the removal range, and a support member on the machine body with its tip facing each end of both sides of the plate in the direction of adjusting the contact pressure with the plate and in the width direction of the plate. A sheet-fed gravure rotary printing machine characterized by being provided with a pair of movably supported auxiliary doctors.