JPH0336025B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink supply device in a printing press that supplies printing ink that has flowed out from an ink fountain and been transferred between rollers to a plate surface on a plate cylinder.

In a printing press, the printing ink stored in the ink fountain flows out from the gap between the fountain roller that rotates inside the ink fountain and the ink blade whose tip is in contact with the circumferential surface of the fountain roller. After being transferred while being smoothed in the circumferential direction and axial direction by rollers and swinging rollers, the ink is supplied to the plate surface on the plate cylinder by a plurality of ink forming rollers. The ink forming roller, which is in contact with the plate surface during printing, separates from the plate surface in conjunction with the unloading operation of the printing cylinder when it enters the non-printing state, and also in conjunction with the retracting operation of the printing cylinder when it transitions to the printing state. It is then placed against the surface of the printing plate.

FIG. 1 is a schematic side view of a single-color double-sided printing offset rotary press as an example of a conventional printing press, and FIGS. 2 and 3 are side views of a conventional ink supply device, respectively. To give an overview of the printing press, the printing unit 2 of the printing press 1 includes:
The upper printing device 3 and the lower printing device 4 are connected to a blanket cylinder 5,
6 are disposed vertically in opposition to each other, and each printing installation 3, 4 is provided with a blanket cylinder 5, 6 as well as a plate cylinder 7, 8 in opposition thereto. A plurality of ink application rollers 9, 10 are removably attached to the peripheral surface of the plate mounted on each plate cylinder 7, 8, and when ink is stored therein, an ink fountain 11, 12
An inking device is provided which includes a roller group (not shown) and which transfers ink to ink forming rollers 9 and 10. In addition, the upper rubber cylinder 5 has a transfer cylinder 1.
3 and the transfer drum 4 are in contact with each other. Then, the sheets of paper fed one by one onto the differential plate 16 by the paper feeding device 15 pass through the swing 17 and the transfer cylinder 13, and are then picked up by the claws of the blanket cylinder 5. On the other hand, since the image formed on the printing plate by the ink forming rollers 9 and 10 and the water supply devices 18 and 19 is transferred to the upper and lower blanket cylinders 5 and 6, respectively, it is held in the claws of the blanket cylinder 5 and conveyed. The images on the blanket cylinders 5 and 6 are transferred to both sides of the paper and double-sided printing is performed, and the printed paper is transferred to the transfer cylinder 1.
4 and the pawl of the paper ejection chain 20 and are conveyed, and then released and dropped onto the paper stacking table 21 to be stacked. When the printing cylinder shifts to the non-printing state, the printing cylinder is first removed from the lower blanket cylinder 6.
is removed from the upper blanket cylinder 5, the transfer cylinder 14 is removed from the upper blanket cylinder 5, and then the transfer cylinder 14 is removed from the upper blanket cylinder 5.
is removed from the plate cylinder 7. Further, as described above, in conjunction with this, the ink forming rollers 9 and 10 are separated from the printing plate on the printing cylinders 7 and 8. Further, when transitioning from the non-printing state to the printing state, this reverse order is used.

However, when the cylinders are attached and detached as described above, the upper rubber cylinder 5 and the transfer cylinder 14, which are equipped with claws for transporting paper, move each time the cylinder is attached and detached, and the paper gripping position is changed. Due to this change, there were problems in that register accuracy could not be ensured, and noise and scratches on the barrel surface were generated when the barrel was attached and removed.

Therefore, an arrangement has been proposed in which the arrangement of the trunks is the same as that shown in FIG. 1, but only the mechanism for attaching and removing the trunks is improved. That is, in this case, in FIG. 1, the lower blanket cylinder 6 is first removed from the upper blanket cylinder 5, and then the lower blanket cylinder 6 is removed from the lower plate cylinder 8, and the upper plate cylinder 7 is removed from the upper blanket cylinder 5. This is for removing the body, and when inserting the body, this is done in the reverse order. By doing so, the body provided with the claws does not move every time the body is attached or detached, and the above-mentioned problem can be solved. An ink supply device that can cope with such a change in the order of attaching and detaching the body has been proposed, and FIGS. 2 and 3 respectively show side views of this type of conventional ink supply device. ing. First, referring to FIG. 2, the plate cylinder 7 is supported by an eccentric bearing whose inner circumferential circle and outer circumferential circle are eccentric by an amount indicated by the symbol t in the figure, and this eccentric bearing can be rotated on the outer circumferential surface. The plate cylinder 7 is configured to be attached to and detached from the upper blanket cylinder 5. When starting the printing work, the air cylinder 22 is activated and the piston rod 23 is activated.
As the L-shaped lever 24 extends, the L-shaped lever 24 rotates counterclockwise in the figure to the state shown in the figure, and the cam lever 25 rotates counterclockwise around the support shaft 26 to occupy the position shown in the figure. Due to the action of the surface 25a and the cam follower 27, the roller arm 28 is rotated by the elastic force of the compression coil spring 29, and the ink forming roller 9 supported by the roller arm 28 is pressed against the plate surface of the plate cylinder 7, and ink is supplied. be done. When the ink has been completely supplied to the entire plate surface, the paper is supplied between the upper blanket cylinder 5 and the lower blanket cylinder 6, and at the same time, the eccentric bearing of the plate cylinder 7 rotates, and the plate cylinder 7 is connected to the upper blanket cylinder 5. It is thrown into the body against the opponent. Moreover, in the case of removing the body, the process is performed in the reverse order.

However, in such a conventional ink supply device, when the plate cylinder 7 is in the unloaded state, the cam lever 25 escapes and the ink forming roller 9 is pressed, so that the plate cylinder 7 is not inserted into the cylinder. The ink form roller 9 will be pressed with a pressure greater than the normal contact pressure at that time, and this overpressure may not only reduce the durability of the ink form roller 9 but also cause the plate cylinder to There has been a problem in that the contact pressure of the ink forming roller 9 changes when the ink forming roller 7 is inserted into the cylinder, which tends to cause printing defects such as shot marks.

Therefore, as shown in Fig. 3, the roller arm 2
8 is provided with a bolt-type stopper 30, and this is brought into contact with the outer periphery of an eccentric bearing 31 that pivotally supports the plate cylinder 7, so that the movement of the ink forming roller 9 follows the movement of the plate cylinder, thereby eliminating the above-mentioned overpressure. However, in this case, not only would it require skill to adjust the stopper 30 and would be impossible to adjust during operation, but also the tip of the stopper 30 or the eccentric bearing 31 could be damaged. Problems may occur, such as the outer peripheral surface being worn out in a short period of time, making adjustment difficult, or the direction of movement of the plate cylinder 7 and the axial direction of the stopper 30 being misaligned, making it difficult to maintain a constant contact pressure. I got a lot of points.

The present invention has been made in view of the above points, and includes a three-stage cam for attaching and detaching the ink forming roller to and from the upper plate cylinder, and the cam is fitted into the concentric portion of the plate cylinder of the eccentric bearing for the upper plate cylinder. This cam and the eccentric bearing for the lower rubber cylinder are connected by a link mechanism including a fluid cylinder, and the rotation of the eccentric bearing and the expansion and contraction of the fluid cylinder rotate the roller attachment/detachment cam in two stages, before and after the cylinder is inserted. With this configuration, changes in the contact pressure of the ink forming roller against the plate cylinder before and during the printing operation are reduced, and overpressure is avoided, improving the durability of the ink forming roller and preventing printing failures. An object of the present invention is to provide an ink supply device for a printing press that enables this with a simple configuration. Embodiments of the present invention will be described in detail below with reference to the drawings.

This embodiment shows an example in which the present invention is applied to a single-color double-sided printing offset rotary printing press. FIG. 4 is a side view thereof, FIG.
The figure is a partially cutaway exploded front view, and FIG. 7 is a side view of the vicinity of the ink forming roller. Of the two printing cylinder attachment and detachment devices described above, this device is applied to the latter device that attaches and detaches the plate cylinder to and from the blanket cylinder. Since this has been explained with reference to FIG. 1, the explanation thereof will be omitted, and will be explained later using the same figure when necessary. In these figures, the frame 41 of the printing unit 2 has an eccentric bearing 42 with a flange, which is eccentric from the axis F of the outer circumferential circle 42a and the axis _F1 of the inner circumferential circle 42b by an amount indicated by the symbol t in the figures. , are rotatably supported on an outer circumferential circle 42a, and a rotating plate cylinder 7, which is driven and connected to the driving side by a cylinder gear 43, is pivotally supported on an inner circumferential circle 42b. Rod 4 pivotally connected to the collar of eccentric bearing 42
4 extends downward, and its lower end is pivotally connected to a lever with a roller (not shown), and the rod is moved vertically via an air cylinder and a cam by a signal from the paper feeder side or by manual push button operation. The eccentric bearing 42 is rotated by moving it forward and backward, and the plate cylinder 7 is attached to and detached from the upper blanket cylinder 5 by its eccentric action. A pair of swing rollers 45 are disposed above the plate cylinder 7 and are pivotally supported by the left and right frames 41. At both ends of each swing roller 45, there are provided a pair of swing rollers 45 as shown in FIGS. 6 and 7. One set of roller arms, an L-shaped roller arm 46 and a roller arm 47 that does not bend in an L-shape, are installed adjacent to each other, and are moved in the axial direction by a nut 48. are regulated. In addition,
Although these roller arms 46 and 47 have different shapes, they have the same structure, so only the roller arm 46 is shown in FIG.
Only the 6th side will be explained. Roller arm 46
is formed with one free end in a split shape,
In the shaft hole of this split part, a roller holder 49 formed in three stages by a bearing part 49a, a shaft part 49b, and a fitting part 49c is fixed by having the shaft part 49b pivotally supported. has been done. This roller holder 49 has an axis F ₂ of a bearing part 49a and a fitting part 49c which are concentric, and an axis F ₃ of a shaft support 49b.
The ink forming roller 9 is rotatably supported on the bearing portion _49a with its circumferential surface facing the circumferential surface of the plate cylinder 7. . Further, a bearing pin 50 formed in a step shape is capped on the fitting part 49c and fixed with a set screw.After loosening the split tightening of the roller arm 46, a spanner is applied to the hole of the bearing pin 50. By rotating, the ink forming roller 9 is eccentrically rotated by an eccentric action, and the contact pressure against the swinging roller 45 and the plate cylinder 7 is set in accordance with the thickness and the like. Further, the small diameter portion and the large diameter portion of the bearing pin 50 are eccentric by the same amount as the eccentricity amount indicated by the symbol _t1 , and the bearing pin 50 is in a state where its eccentric phase is the same as the eccentric phase of the roller holder 49. The small diameter portion of the ink forming roller 9
A cam follower 51 is fitted and fixed to the small diameter portion concentric with the cam follower 51 . A spring shaft 52 is fixed to the frame 41 with bolts and slidably supported by a protruding post 53, and its lower end is connected to the other free end of the roller arm 46 with a pin 54.
A compression coil spring 5 is mounted on the spring shaft 52 for applying a rotational force to the roller arm 46 in the direction of pressing the ink forming roller 9 against the plate cylinder 7.
5 is installed. Further, on the threaded portion of the spring shaft 52 protruding from the post 53, there is an adjusting nut 56 for adjusting the contact pressure of the ink forming roller 9 against the plate cylinder 7.
are screwed together, and a groove is provided on the outer periphery where the wrench hole is provided to engage the protrusion of the locking leaf spring 57.

The ink form roller device configured in this manner is provided with a detachable device for attaching and detaching the ink form roller 9 to and from the plate cylinder 7.
and a drive device 61 that rotates this. First, the roller attachment/detachment cam 60 is integrally formed with a disc-shaped cam body and a boss fitted into a circular hole of the cam body and fixed with a set screw, and the boss projects inward of the frame 41. The eccentric bearing 42
It is rotatably fitted into the outer circumferential step portion 42c of.
Note that the outer circumferential step portion 42c is formed concentrically with the inner circumferential circular axis _F1 of the eccentric bearing 42, that is, the axis of the plate cylinder 7. Furthermore, three elongated holes 62 are drilled in the cam body, dividing the circumferential direction into three equal parts, and a bushing 63 with a flange fitted into the elongated holes 62 is attached to the frame by bolts. It is fixed at 41. By doing this, the roller attachment/detachment cam 60 is restricted from moving in the axial direction, and the bushing 60 is restricted from moving in the axial direction.
By making the outer diameter of the plate cylinder 3 sufficiently smaller than the inner diameter of the elongated hole 62, the plate cylinder 7 is configured to be able to move following the eccentric movement of the plate cylinder 7. The outer circumferential cam surface of the roller attachment/detachment cam 60 mounted in this manner is formed in three steps for each ink forming roller 9, including a large diameter portion 60a, a medium diameter portion 60b, and a small diameter portion 60c. , the diameter of each part is set as follows. That is, the large diameter portion 60a is
A cam surface that brings the cam follower 51 into contact when the plate cylinder 7 is removed from the blanket cylinder 5,
At this time, the ink forming roller 9 is set to be separated from the plate cylinder 7. Also, the middle diameter portion 60b
is a cam surface that makes the cam follower 51 come into contact with the cam follower 51 just before the plate cylinder 7 is inserted into the blanket cylinder 5 and during the insertion operation, so that the ink forming roller 9 is pressed against the plate cylinder 7 at this time. is set to . Note that the cam follower 51 has a large diameter portion 60a and a medium diameter portion 6.
0b, the roller arm 46 compresses the compression coil spring 55, and a gap is formed between the adjustment nut 56 and the post 53. Furthermore, the small diameter portion 60c is a cam surface that makes the cam follower 51 come into contact with the plate cylinder 7 when the insertion of the plate cylinder 7 into the blanket cylinder 5 is completed, and at this time, the ink forming roller 9 is in pressure contact with the plate cylinder 7, and The adjustment nut 56 is in contact with the post 53,
The ink forming roller 59 is pressed against the plate cylinder 7 by a preset spring pressure of a compression coil spring.

The drive device 61 that drives the rotation of the roller attachment/detachment cam 60 configured in this way includes an air cylinder 64.
The air cylinder 64 includes a lower rubber cylinder 6 disposed below and facing the upper rubber cylinder 5.
It is rotatably supported by a pin 66 on the outer periphery of an eccentric bearing 65 that pivotally supports the. Note that the eccentric bearing 65 has an axis F ₄ of an outer circumferential circle 65a supported by the frame 41 in the same way as the eccentric bearing 42, and a rubber cylinder 6.
The axis _F5 of the inner circumferential circle 65b which supports the axis is _t2 in the figure.
It is eccentric as indicated by . A rod end 68 screwed into the working end of the piston rod 67 of the air cylinder 64 is a free end of a lever 70 that projects radially from the tip of a lever shaft 69 rotatably mounted between the left and right frames 41. The lever shaft 6 is pivoted by the expansion and contraction of the piston rod 67.
9 is configured to reciprocate in forward and reverse directions. 71 is fixed to the frame 41 and the lever shaft 6
This is a bracket that supports the protrusion 9. The lever shaft 69 and the roller attachment/detachment cam 60 are connected to a lever 72 fixed to the lever shaft 69 and a pin 7 at both ends.
It is connected like a link with a connecting rod 75 which is pivotally mounted at 3 and 74. By doing this, the eccentric bearing 65 can be rotated, and the air cylinder 64 can be rotated.
The roller attachment/detachment cam 60 rotates by expanding and contracting the piston rod 67, but the relationship between the position of the pin 66, which is the pivot center of the air cylinder 64, and the phase of the roller attachment/detachment cam 60 is set as follows. has been done. That is, when the eccentric bearing 65 is rotated to remove the lower blanket cylinder 6 from the upper blanket cylinder 5, the pin 66 moves from 66a to 66c in FIG.
The phase of the pin 66 is set so that the pin 66 moves up to a point 66c and crosses the dead center just before the end of movement 66c. Further, the position where the roller attachment/detachment cam 60 contacts the cam follower 51 is the small diameter portion 60c when the pin 66 is at the position 66a, and the medium diameter portion when the pin 66 is at 66b and 66c near the dead center. 60b, and the opposing position of the cam follower 51 is set to the middle diameter portion 60b.
The roller attachment/detachment cam 60 is rotated by the expansion and contraction of the piston rod 67 to move the roller attachment/detachment cam 60 from the piston rod 60a to the large diameter portion 60a. In addition, pin 6
6 reaches 66b just before the dead center, another cam mechanism moves the axis _F1 of the upper blanket cylinder 7 via the rod 44 and the eccentric bearing 42, and moves it relative to the upper blanket cylinder 5. The timing is set so that the body is removed.

The operation of the ink supply device configured as above will be explained. Prior to printing, the plate cylinder 7, lower blanket cylinder 6, and ink forming roller 9 are manually inserted, and then the ink is applied to the plate cylinder 7 by rotating the nut 56 and expanding and contracting the compression coil spring 55. Adjust the contact pressure of the deposition roller 9. After rotating the eccentric bearing 65 to move the position of the pin 66 from point 66a to point 66b, the set screw of the bearing pin 50 of the ink application roller 9 is loosened, and the bearing pin 50 is rotated to apply the ink. The contact state between the cam follower 51 and the cam 60 is adjusted to match the diameter of the roller 9. Then, manually remove the plate cylinder 7 from the blanket cylinder 5, and manually remove the ink forming roller 9 from the plate cylinder 7.
The lower blanket cylinder 6 is removed from the upper blanket cylinder 5 and the lower plate cylinder 8. FIG. 4 shows this state, where the pin 66 is at a point 66c near the dead center and the piston rod 67 is extended. Therefore, the cam follower 51 is in contact with the large diameter portion 60a of the roller attachment/detachment cam 60, and the ink forming roller 9 is spaced apart from the plate cylinder 7.

In this state, when the cylinder attachment/detachment is switched to automatic and printing work is started, the air cylinder 64 is activated by a signal from a timing regulating device (not shown) and the piston rod 67 is contracted, so that the roller attachment/detachment cam 60 is connected to the eccentric bearing via the link mechanism. 42 outer peripheral surface 42c
Then, the cam follower 51 is rotated counterclockwise in FIG. Therefore, the ink forming roller 9 is pressed against the plate surface of the plate cylinder 7 by the swinging of the roller arms 46 and 47 due to the elastic force of the compression coil spring 55, and ink is supplied. In this case, since the medium diameter portion 60b serves as a stopper, the contact pressure of the inking roller 9 does not become excessive. A moment later, the eccentric bearing 65 of the lower blanket cylinder 6 begins to rotate counterclockwise in FIG.
b, and the lower blanket cylinder 6 is inserted into the lower plate cylinder 8. At this time, the eccentric bearing 42 of the plate cylinder 7 is rotated by another mechanism, and the plate cylinder is inserted into the upper blanket cylinder 5 due to its eccentric action. In this case, pin 66
Even if the air cylinder 64 moves, the movement component in the axial direction of the air cylinder 64 can be almost ignored before and after the dead center.
Therefore, the roller attachment/detachment cam 60 does not rotate, and the cam follower 51 remains in contact with the middle diameter portion 60b. Further, the ink attachment/detachment cam 60 is fitted onto the outer circumferential surface 42c concentric with the plate cylinder 7, and moves eccentrically following the movement of the plate cylinder 7, so that the ink forming roller 9 and the plate cylinder 7 are connected before and after insertion. Since the phase position does not change,
The contact pressure of the ink forming roller 9 does not change. Further, as the roller attachment/detachment cam 60 rotates, the elongated hole 62 is displaced with respect to the bolt fixed to the frame 41, but by making the bush 63 sufficiently smaller in diameter than the elongated hole 62, this movement can be prevented. There is no. Incidentally, the adjustment nut 56, which had been separated from the post 53 before the cylinder insertion, no longer has a gap with the post 53 when the plate cylinder 7 is completely installed. After the plate cylinder 7 is completely loaded, the eccentric bearing 65 of the lower blanket cylinder 6 continues to rotate for loading, and the pin 66 moves from the point 66b to the point 66a. Therefore, the roller attachment/detachment cam 60 further rotates via the link mechanism including the air cylinder 64 in which the piston rod 67 remains contracted, and the cam follower 51 comes into contact with the small diameter portion 60c. In this case, since the ink forming roller 9 is in pressure contact with the plate cylinder 7, the roller arms 46 and 47 do not rotate any further, and the cam follower 51 is separated from the small diameter portion 60c of the cam surface, and the adjustment nut is 56 continues to be in contact with the post 53, a predetermined contact pressure preset in the compression coil spring 55 is applied to the inking roller 9. As the eccentric bearing 65 rotates in this manner, the lower rubber cylinder 6 is inserted into the upper rubber cylinder 5, thereby completing the overall insertion operation. Then, in parallel with the ink being supplied to the printing plate, dampening water is supplied from the water supply device to form an image on the printing plate, which is transferred to the upper and lower blanket cylinders 5 and 6 and onto the paper passing between them. On the other hand, double-sided printing is performed.

Then, when the printing operation is completed or when paper feeding is stopped due to a paper feeding error or the like, the barrel removal is performed in the completely reverse order of the barrel insertion in response to a signal from the timing regulating device. That is, the lower rubber cylinder 6 is removed from the upper rubber cylinder 5 and the cam 60 is removed.
The large diameter portion 60a of the cam 60 is rotated to the middle diameter portion 60b, the upper plate cylinder 7 is removed, the lower blanket cylinder 6 is removed from the lower plate cylinder 8, the pin 66 is moved beyond the dead center, and the piston rod 67 is extended. The rotation of the ink forming roller 9 and the removal of the body of the ink forming roller 9 are performed in this order.
In the case of body removal, as in the case of body insertion, the roller attachment/detachment cam rotates at the same time as the plate cylinder 7 is removed, and the cam follower 51 comes into contact with the medium diameter portion 60b of the cam surface, so that the ink forming roller 9 is attached to the plate cylinder. It follows the movement of plate cylinder 7 and escapes from plate cylinder 7, so that the contact pressure does not become excessive.

Although this embodiment shows an example in which the present invention is applied to a single-color printing press, it can also be applied to a multi-color printing press.

As is clear from the above description, according to the present invention, in the ink supply device of a printing press, the cam for attaching and detaching the ink form roller to and from the upper plate cylinder is formed in three steps, and the plate of the eccentric bearing for the upper plate cylinder is formed. This cam is fitted in the concentric part of the cylinder, and this cam and the eccentric bearing for the lower plate cylinder are connected by a link mechanism including a fluid cylinder, and the rotation of this eccentric bearing and the expansion and contraction of the fluid cylinder move the roller attachment/detachment cam before and after insertion into the cylinder. By configuring the ink form roller to rotate in two stages, the contact pressure of the ink form roller does not become excessive when the plate cylinder is attached or removed, and the durability of the ink form roller is significantly improved. The ink forming roller moves to follow the movement of the ink forming roller, and the contact pressure of the ink forming roller does not change before and after attaching and detaching the body. This prevents printing defects such as scratches and improves the quality of printed matter. . In addition, the eccentric bearing for attaching and detaching the lower blanket cylinder is skillfully used to drive part of the ink form roller attachment and detachment operation, which simplifies the structure and shortens the stroke of the fluid cylinder for attachment and detachment. Its size can be reduced.

[Brief explanation of drawings]

Fig. 1 is a schematic side view of a single-color double-sided offset rotary printing press, Figs. 2 and 3 are side views of a conventional ink supply device, and Figs. Fig. 4 shows a side view of the supply device, Fig. 5 is a partially cutaway exploded plan view, Fig. 6 is a partially cutaway exploded front view, and Fig. 7 shows the ink deposition. FIG. 3 is a side view of the vicinity of the roller. 5... Upper rubber cylinder, 6... Lower rubber cylinder, 7...
Upper plate cylinder, 8...Lower plate cylinder, 9...Ink forming roller, 26, 27...Roller arm, 42...Eccentric bearing, 42c...Outer peripheral step, 51...Cam follower, 52...Compression coil spring , 56...Natsuto,
60...Roller attachment/detachment cam, 60a...Large diameter portion, 6
0b...Medium diameter part, 60c...Small diameter part, 64...Air cylinder, 65...Eccentric bearing, 70...Lever, 72...Lever, 75...Connection rod.

Claims (1)

[Claims] 1. An upper plate cylinder which is supported by an eccentric bearing and is attached to and detached from the upper blanket cylinder by the rotation of the eccentric bearing, and which is supported by a swingable roller arm and which is attached to and detached from the upper blanket cylinder by the swing of the roller arm. and a lower blanket cylinder which is rotatably supported by an eccentric bearing and which is attached to and detached from the upper blanket cylinder and the lower plate cylinder by rotation of the eccentric bearing. a roller attachment/detachment cam rotatably fitted in a plate cylinder concentric circle of an eccentric bearing that pivotally supports the upper plate cylinder and has an outer circumferential cam surface that brings the cam follower into contact with the cam follower; a contact pressure adjusting means for the ink forming roller including a spring member that applies rotational force to the roller arm, and the cam surface is brought into contact with the cam follower when the upper plate cylinder is removed, so that the ink forming roller can be adjusted to the upper plate cylinder. A large diameter part that is separated from the cylinder, a medium diameter part that brings the ink formation roller into contact with the upper plate cylinder by bringing the cam follower into contact with the cam follower just before the upper plate cylinder is loaded and during the cylinder loading operation, and a middle diameter part that makes the ink forming roller face the upper plate cylinder. When completed, the ink attachment/detachment cam and the lower blanket cylinder eccentric bearing are connected by a link mechanism including a fluid cylinder. An ink supply device for a printing press, characterized in that the two-step rotation of an ink attachment/detachment cam is driven one step each by rotation of an eccentric bearing for a lower blanket cylinder and expansion/contraction of a fluid cylinder.