JPH0781039A - Printing cylinder of sheet-fed press - Google Patents

Abstract

PURPOSE:To provide the printing cylinder of a sheet-fed press capable of easily and certainly winding a blanket around cylinder to fix the same while suppressing a gripper margin to the min. CONSTITUTION:A rubber blanket 10 is wound around the outer peripheral surface 4M of a cylinder 4 and the gripper head side 10a of the rubber cylinder 10 is inserted in an insertion space 7S to be hooked with a press part 6. A pawl stand 3 is moved in the direction shown by an arrow 95 from this state and the gripper head side 10a of the rubber blanket 10 is held and fixed between the inner wall 4T of the cylinder 4 and the side surface 3T of the pawl stand 3. Therefore, the width of the gripper margin of a sheet held between a pawl and the upper end surface 3M of the pawl stand 3 may be set to the interval 7S. That is, the gripper margin can be suppressed to the min. and, moverover, the rubber blanket 10 can be easily fixed to the cylinder 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a printing cylinder of a sheet-fed printing machine in which a cylinder around which a blanket is wound is provided with a claw mechanism for holding a sheet, and particularly, while a gripper margin is reduced, The present invention relates to a structure for easily and surely winding and fixing a blanket.

[0002]

2. Description of the Related Art A conceptual view of each printing cylinder in a sheet-fed printing press is shown in FIG. This drawing shows a sheet-fed offset printing press as an example. A plate 81 is wound around the outer peripheral surface of the plate cylinder 80, and ink and water are supplied to the plate 81. A rubber blanket cylinder 82 is close to the plate cylinder 80, and the rubber blanket 70 wound around the outer peripheral surface and the plate 81 are in contact with each other. The plate cylinder 80 and the blanket cylinder 82 rotate about the cylinder axes 80J and 82J, respectively.

Sheets of paper 85 that are successively fed are wound around the impression cylinder 84, and the sheets of paper 85 and the rubber blanket 70 come into contact with each other. In the offset printing, the ink on the plate 81 is temporarily transferred to the rubber blanket 70,
Further, the sheet of paper 85 is moved to and printed. Impression cylinder 84
A plurality of claws 71 for sandwiching the sheet 85 are provided in the axial direction. The impression cylinder 84 holds the sheets 85 one after another with the claw 71 while rotating around the cylinder shaft 84J, and prints with the ink from the rubber blanket 70.

Some sheet-fed printing presses perform printing using a printing cylinder that also serves as an impression cylinder and a rubber blanket cylinder. A side sectional view of the printing cylinder 72 is shown in FIG. The cylinder 73 is provided with a pawl shaft 71J.
A plurality of claws 71 are fixed to J. The claw 71 is a claw shaft 71
It pivots around J and opens to form a sandwiching space 71S with the claw stand 74. And this sandwiching space 71S
When the leading end of the sheet 85 is guided to the sheet, the claw 71 is closed and the sheet 85 is sandwiched for printing.

Before performing a printing operation, a rubber blanket 70 is wound around and fixed to the outer peripheral surface of the cylinder 73. FIG. 8 shows a state in which the rubber blanket 70 is wound and fixed. When winding the rubber blanket 70, first, the gripper cassette 79 in which the claw base 74, the claw shaft 71J, and the claw 71 are integrated is removed from the cylinder 73. By removing the cap bolts N1 and N2, the gripper cassette 79 can be pulled out in the direction of arrow 90.

After removing the gripper cassette 79, the head side 70a of the rubber blanket 70 is inserted into the space. An aluminum bar 69a for fixing is provided on an end side of the rubber blanket 70 on the head side 70a, and the aluminum bar 69a is hooked on a hook on the cylinder side. Then, the gripper cassette 79 is inserted in the direction of the arrow 91, and the cap bolts N1 and N2 are tightened to fix the head side 70a of the rubber blanket 70 as shown in FIG.

Next, the printing cylinder 72 is rotated and the rubber blanket 70 is wound around the outer peripheral surface of the cylinder 73. And, the tail side 70b of the rubber blanket 70
The aluminum bar 69b provided on the end side of is attached to the hook of the mounting base 75, and is pressed by the fixed aluminum bar 78 to tighten the bolt 76. If the rubber blanket 70 is simply wound in this way, the rubber blanket 70 is slackened, and a gap remains between the outer peripheral surface of the cylinder 73. FIG. 9 shows a state in which the slack spaces Y1 and Y2 are generated. If such slack spaces Y1 and Y2 remain between the cylinder 4 and the outer peripheral surface 4M, ink adheres to unnecessary portions of the sheet during printing and causes cylinder printing, thus improving print quality. Lower.

Therefore, after fixing the tail edge side 70b of the rubber blanket 70, the tension bolt 77 is tightened. By this tightening, the tail edge side 70b of the rubber blanket 70 moves in the direction of the arrow 92 around the platform central axis 75J, tension is applied to the rubber blanket 70, and the slack spaces Y1 and Y2 are eliminated. In order to completely eliminate the slack spaces Y1 and Y2 of the rubber blanket 70, the idling rotation of the printing cylinder 72 is repeated, and the slack is moved toward the tail edge side 70b by the pressure with the adjacent printing cylinder. Then, the tightening of the tension bolt 77 is repeated several times, and the slack space Y1 generated near the gripping head side 70a is also eliminated.

After the rubber blanket 70 is stretched on the outer peripheral surface of the cylinder 73 as described above, the printing operation is started.

[0010]

The conventional printing cylinder has the following problems. When the rubber blanket 70 is wound, the cap bolts N1 and N2 are first loosened and the gripper cassette 79 is removed from the cylinder 73 as described above. The head side 70a of the rubber blanket 70
After inserting, the gripper cassette 79 is attached and the cap bolts N1 and N2 are tightened. This cap bolt N
A plurality of Nos. 1 and N2 are provided in the axial direction, for example, four to six, and it takes time to loosen and tighten these bolts. As described above, when fixing the rubber blanket 70 to the cylinder 73, it is necessary to remove the entire gripper cassette 79 from the cylinder 73.
There is a problem that workability is reduced.

For this reason, for example, instead of pressing the gripping head side 70a of the rubber blanket 70 with the gripper cassette 79 to fix it, it is possible to fix it with bolts or the like. In this case, as shown in FIG. 10, it is necessary to provide a wide gap 74S between the claw base 74 and the inner wall 73T of the cylinder 73. That is, after the head side 70a of the rubber blanket 70 is inserted into the gap 74S, the inner wall 73 of the cylinder 73 is inserted through the gap 74S by a bolt or the like (not shown).
Fix at T. If such a mechanism is adopted, it is not necessary to attach / detach the entire gripper cassette, and it is possible to prevent a decrease in work efficiency.

However, when the mechanism shown in FIG. 10 is adopted, the following new problems occur. As described above, the claw 71 opens and closes to sandwich the sheet with the claw base 74. And this sheet is a rubber blanket 70
It is wrapped around and printed.

Here, when the distance 74S between the claw stand 74 and the inner wall 73T of the cylinder 73 is wide as shown in FIG. 10, the gripper margin at the edge of the sheet is correspondingly widened. That is, since there is no support from the back surface at the end portions of the sheet corresponding to the interval 74S, reliable printing cannot be performed, and a new problem that a gripper margin as an unprintable area must be secured widely. Occurs. In the printing cylinder 72 shown in FIG. 8, the gripper cassette 79 is used.
Since the head side 70a is fixed by attaching and detaching, the gripper margin 74G can be minimized, but there is a problem that the work efficiency is poor as described above.

Therefore, an object of the present invention is to provide a printing cylinder of a sheet-fed printing press that can easily and reliably wind and fix a blanket around a cylinder while minimizing a gripper margin.

[0015]

A printing cylinder of a sheet-fed printing press according to the present invention is embedded in a cylinder around which a blanket is wound around an outer peripheral surface of the cylinder, and the upper end surface thereof is substantially flush with the outer peripheral surface of the cylinder. And a side surface facing the inner wall of the cylinder, the sheet holding table holding and fixing the first end of the blanket between the side surface and the inner wall of the cylinder. , Provided on the cylinder,
Printing on a sheet-fed printing press provided with a sheet-holding piece for sandwiching the fed sheet by an opening / closing operation between the sheet-holding table and an upper end surface of the sheet-holding table, and a fixing portion for fixing the second end of the blanket. The cylinder is characterized in that the sheet holding table is provided with an opening / closing operation portion that opens in a direction away from the inner wall of the cylinder or closes in a direction toward the inner wall of the cylinder.

[0016]

In the printing cylinder of the sheet-fed printing press according to the present invention,
The opening / closing operation portion opens the sheet holding table in a direction away from the inner wall of the cylinder or closes it in a direction toward the inner wall of the cylinder.

Therefore, the sheet holder is opened and the first end of the blanket is inserted between the side of the sheet holder and the inner wall of the cylinder, after which the sheet holder is closed and the blanket of the blanket is closed. The first end can be fixed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a printing cylinder of a sheet-fed printing press according to the present invention will be described with reference to FIGS. FIG. 1 is a plan view of a printing cylinder 2 in this embodiment, and FIG.
It is a side sectional view in the II-II direction. FIG. 2 shows a state in which the slack of the rubber blanket 10 is removed by the tensioning mechanism, and the printing operation is started from this state. In addition, the printing cylinder shown in the figure doubles as an impression cylinder and a rubber blanket cylinder, and is provided with a claw 7 for sandwiching a sheet, and a rubber blanket 10 is wound around the outer peripheral surface 4M of the cylinder. To be

In this embodiment, from the state shown in FIG.
Is moved in the direction of arrow 95 to hold and fix the haggling side 10a of the rubber blanket 10 between the inner wall 4T of the cylinder 4 and the side surface 3T of the claw base 3. In this way, by holding the head side 10a of the rubber blanket 10 by moving the claw base 3, the width of the gripper margin of the sheet sandwiched between the claw 7 and the upper end surface 3M of the claw base 3 can be reduced. It is intended to minimize and yet to easily fix the rubber blanket 10 to the cylinder 4. The details will be described below.

FIG. 3 shows the printing cylinder 2 before winding the rubber blanket 10. The cylinder 4 of the printing cylinder 2 rotates around a cylinder axis 4J. Further, a claw shaft 7J is provided in the cylinder 4, six claw holders 7H are fixed to the claw shaft 7J, and further, a claw 7 as a sheet holding piece is fixed to each claw holder 7H. (See Figure 1).

At a position where the six claws 7 contact, a claw base 3 as a sheet holding table is embedded. The upper end surface 3M of the claw base 3 is located substantially on the same plane as the outer peripheral surface 4M of the cylinder 4, and the side surface 3T is located opposite the inner wall 4T of the cylinder 4.

When performing the printing operation, the printing cylinder 2 winds the sheet around the rubber blanket 10 while rotating around the cylinder shaft 4J, and prints with the ink adhering to the rubber blanket 10. The claw 7 opens and closes at the timing of the sheets that are successively fed, and holds the sheets between the claw 7 and the upper end surface 3M of the nail base 3 to hold and print.

An insertion space 7S is formed between the claw base 3 and the inner wall 4T of the cylinder 4 for inserting the haggling side which is the first end of the rubber blanket 10, and the pressing space is provided inside. 6 is located. The claw base 3 can be moved in a direction away from the inner wall 4T of the cylinder 4 (direction of arrow 94) by the opening / closing bolt 13 as an opening / closing operation portion, and the insertion space 7S can be widened from the state shown in FIG.
Further, it can also be moved in a direction approaching the inner wall 4T (direction of arrow 95) by the opening / closing bolt 13. Since a retaining pin 13P is provided at the tip of the opening / closing bolt 13 to limit the screwing of the opening / closing bolt 13, the opening / closing bolt 13 will not fall out, and the claw base 3 will not be separated from the cylinder 4. Absent.

A tension shaft 8J is provided in the cylinder 4, and a tension holder 8 as a fixed portion is attached to the tension shaft 8J.
Is rotatably attached. A holding space 8S is formed in the tension holder 8 by the holding piece 8K, and the tail end side which is the second end of the rubber blanket 10 is held therein. A tension bolt 12N of a knob 12 is screwed into and penetrates the tension holder 8. By loosening the knob 12, the tension holder 8 is moved from the state shown in FIG.
It can be rotated around J in the direction of arrow 96. Further, by tightening the knob 12, the knob 12 can be rotated in the direction of the arrow 97 to return to the state of FIG.

Next, a rubber blanket 1 is attached to the printing cylinder 2.
A specific procedure for winding 0 will be described. First, the screw 7N shown in FIG. 1 is loosened, and the claw holder 7H is opened in the direction of arrow 99 with the claw shaft 7J as the center. The screw 7N is loosened through the cracked portion of the tip of the transmission portion 17 that is integrally fixed to the claw holder 7H, and the transmission portion 17 is pushed up by the screw 7N to open the claw holder 7H. FIG. 4 is a sectional view taken along the line IV-IV in FIG. 1, in which the screw 7N is loosened to a position where the claw holder 7H abuts on the stopper pin 20 (position indicated by a dotted line). Note that FIG.
In, the other parts are omitted.

After opening the claw holder 7H, the opening / closing bolt 13 is subsequently loosened. When the open / close bolt 13 is loosened, the spring F
The nail base 3 is pressed by 3 (FIG. 1), and the nail base 3 moves in the direction of arrow 94 (FIG. 3) to a position where it hits the nail holder 7H. In this way, the nail base 3 is opened to secure a large insertion space 7S (see FIG. 5). Then, the knob 12 is loosened, and the tension holder 8 is rotated in the direction of arrow 96 from the state shown in FIG. 3 around the tension shaft 8J. In this case, the tension holder 8 is rotated by the restoring force of a spring (not shown).

FIG. 5 shows a state in which the claw base 3 is opened and the tension holder 8 is rotated as described above. FIG. 5 is an arrow in FIG.
It is a cross-sectional view in the VV direction. Next, as shown in FIG.
The rubber blanket 10 is wound around the outer peripheral surface 4M of the cylinder 4. An aluminum bar 30a for fixing is provided on an end side of the rubber blanket 10 on the head side 10a. Then, the head side 10a is inserted into the insertion space 7S, and the aluminum bar 30a is hooked in the hooking recess formed in the pressing portion 6.

After that, the open / close bolt 13 is tightened, and the claw base 3 is tightened.
Is moved in the direction of arrow 95 to close the insertion space 7S (see FIG. 3), and the gripping head side 10a of the rubber blanket 10 and the aluminum bar 3 are interposed between the claw stand 3 and the inner wall 4T of the cylinder 4.
Hold 0a in between and fix. Further, the screw 7N is tightened, and the claw holder 7H is closed in the arrow 98 direction. On the other hand, an aluminum bar 30b for fixing is also provided on the edge side of the tail edge side 10b of the rubber blanket 10, and the aluminum bar 30b is hooked in the hooking space 8S of the holder 8.

Thus, both ends of the rubber blanket 10 are held, and the rubber blanket 10 is fixed to the outer peripheral surface 4M of the cylinder 4.
Wrap along. In this state, as shown in FIG. 5, slack spaces W1 and W2 are formed on the head side 10a and the tail side 10b of the rubber blanket 10, respectively.

Therefore, first, the knob 12 is tightened and the tension holder 8 is rotated in the direction of arrow 93. By this rotation of the tension holder 8, the tail edge side 10b of the rubber blanket 10 is pulled, the slack space W2 is eliminated, and the rubber blanket 10 near the tail edge side 10b comes into close contact with the outer peripheral surface 4M.

However, at this stage, due to the friction between the rubber blanket 10 and the outer peripheral surface 4M, the slack space W1 generated on the head side 10a cannot be eliminated. In particular, when a new rubber blanket 10 is used, a large slack space W1 often occurs due to the rubber strainer. If such a slack space W1 remains between the outer peripheral surface 4M of the cylinder 4 and the printing, the printing quality is deteriorated by causing a cylinder impression in which ink adheres to an unnecessary portion of the sheet during printing. .

Therefore, the pressing screw 32 is finally tightened. The pressing screws 32 are provided at both ends of the printing cylinder 2 as shown in FIG. 1, and are located in contact with the pressing portion 6. By tightening the pressing screw 32, the pressing portion 6 is pushed down toward the cylinder shaft 4J in the direction of arrow 91. FIG. 6 is a part of an axial sectional view of the printing cylinder 2, and FIG.
2 shows a state before tightening the screw 2, and FIG. 6B shows a state after the pressing screw 32 is tightened and the pressing portion 6 is pushed down.

By depressing the pressing portion 6 in the direction of arrow 91, the slack space W1 generated on the gripping side 10a of the rubber blanket 10 is eliminated. FIG. 2 shows a state in which the slack space W1 is eliminated. That is, the head side 10a and the aluminum bar 30a are pulled by the length of the movement space 6S on the bottom surface side of the pressing portion 6 shown in FIG. 5, and the slack space W1 is eliminated.

As described above, in this embodiment, the nail base 3
Is moved in the directions of arrows 94 and 95, and the inner wall 4 of the cylinder 4 is moved.
The head side 10a of the rubber blanket 10 is held and fixed between T and the side surface 3T of the nail base 3. Therefore, the width of the gripper margin of the sheet sandwiched between the claw 7 and the upper end surface 3M of the claw base 3 may be only the interval 7S. That is,
The gripper margin can be minimized, and the rubber blanket 10 can be easily fixed to the cylinder 4.

The present invention is not limited to the structure described in the above embodiment, but other structures can be adopted as long as the rubber blanket 10 can be fixed by moving the claw stand and the gripper margin can be reduced. You may.

[0036]

In the printing cylinder of the sheet-fed printing press according to the present invention, the opening / closing operation portion opens the sheet holding base in the direction away from the inner wall of the cylinder or approaches the inner wall of the cylinder. Close to.

That is, the sheet holder is opened and the first end of the blanket is inserted between the side surface of the sheet holder and the inner wall of the cylinder, after which the sheet holder is closed to close the blanket. The first end can be fixed.

In this way, by operating the opening / closing operation portion to open / close the sheet holding table, the first blanket can be easily set.
The ends can be fixed. Further, the first end of the blanket is fixed by closing the sheet holding table in a direction approaching the inner wall of the cylinder. Therefore, when the sheet holding piece sandwiches the sheet between the sheet holding piece and the upper end surface of the sheet holding base, the gripper margin can be minimized, and a wide sheet printing area can be secured. be able to.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a printing cylinder of a sheet-fed printing press according to the present invention.

FIG. 2 is a side sectional view of the printing cylinder shown in FIG. 1 taken along arrow II-II.

FIG. 3 is a side sectional view showing the printing cylinder of FIG. 1 in a state where a rubber blanket is not wound.

FIG. 4 is a side sectional view of the printing cylinder shown in FIG. 1 taken along arrow IV-IV.

5 is a side cross-sectional view of the printing cylinder shown in FIG. 1 taken along arrow VV.

6 is a part of an axial cross-sectional view of the printing cylinder shown in FIG.

FIG. 7 is a conceptual diagram of each printing cylinder in a sheet-fed offset printing machine.

FIG. 8 is a diagram showing an example of a conventional printing cylinder.

9 is a diagram showing a state where a slack space is generated in a rubber blanket in the printing cylinder shown in FIG.

FIG. 10 is a view showing a mechanism in the case where the gripping head side of the rubber blanket is fixed using a bolt or the like.

[Explanation of symbols]

 2 ... Printing cylinder 3 ... Nail base 3M ... Top surface 3T ... Side surface 4 ... Cylinder 4T ... Inner wall 4M ...・ Outer peripheral surface 7: Claw 8: Tension holder 10: Rubber blanket 13: Opening / closing bolt

Claims (1)

[Claims] 1. A cylinder in which a blanket is wound around an outer peripheral surface, which is embedded in the cylinder, and whose upper end surface is substantially flush with the outer peripheral surface of the cylinder and whose side surface is positioned opposite to the inner wall of the cylinder. A sheet holding table for holding and fixing the first end of the blanket between the side surface and the inner wall of the cylinder, which is provided in the cylinder, and is provided with the sheet to be supplied. In the printing cylinder of the sheet-fed printing press, which comprises a sheet-holding piece that is sandwiched between the upper end surface of the sheet-holding table by opening and closing operation, and a fixing portion that fixes the second end of the blanket, A printing cylinder of a sheet-fed printing press, comprising an opening / closing operation unit that opens in a direction away from the inner wall of the cylinder or closes in a direction toward the inner wall of the cylinder.