JP2006150683A - Offset printing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an offset printing machine which can certainly supply paper to a transfer cylinder from a paper supply part through a swing mechanism, under a simple constitution, even in case the printing speed is accelerated. <P>SOLUTION: In this offset printing machine, the swing mechanism 10 for supplying a sheet P from the paper supply part to the transfer cylinder 14, is equipped with a swing lever 11 which rocks until it delivers the sheet P to a click part of the transfer cylinder 14, holding the tip of the sheet P, and a swing pawl opening/closing device 20 structured of a cam 21 which opens/closes the swing pawl 13 to a click base 12 in accordance with the rocking position of the swing lever 11, a first roller 22 and a second roller 23. The cam 21 formed as a grooved cam enables the sheet P to be certainly delivered from the paper supply part to the transfer cylinder 14 by the swing mechanism 10, as either one of the first roller 22 or the second roller 23 is kept in close contact with an inner cam surface 21a or an outer cam surface 21b, even in case the printing speed is accelerated. Thus it is possible to prevent the printing efficiency from deteriorating. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a multicolor offset printing machine, and more particularly to an offset printing machine including a swing mechanism for intermittently delivering a sheet conveyed from a sheet feeding unit to a transfer cylinder.

Conventionally, for example, a sheet-fed multicolor printing offset printing machine according to Patent Document 1 is configured as shown in FIG.
In FIG. 4, the offset printing machine 1 includes printing units 1a, 1b, 1c, and 1d for each color of yellow, magenta, cyan, and black, for example. In FIG. 4, in order to make the configuration easy to see, detailed configurations such as an inking portion and a water immersion portion are omitted.
The printing units 1a to 1d include plate cylinders 2a to 2d, blanket cylinders 3a to 3d, and impression cylinders 4a to 4d, respectively, and intermediate cylinders 5a, 5b, and 5c are provided between the impression cylinders 4a to 4d. I have.

  Further, a paper feed unit 6 is provided at the front stage of the printing unit 1a, and a paper discharge unit 7 is provided at the rear stage of the printing unit 1d. As a result, the sheet A is fed from the paper feed section 6 between the blanket cylinder 3a and the plate cylinder 2a of the first printing unit 1a through the paper feed table 6a, the swing mechanism 6b and the transfer cylinder 6c. Then, the sheet A is discharged from the impression cylinder 4d of the last printing unit 1d onto the discharge table 7c of the discharge unit 7 through the delivery cylinder 7a and the chain gripper 7b.

  The printing units 1a to 1d have the same configuration, and printing ink is applied to a printing plate (not shown) mounted along the peripheral surfaces of the plate cylinders 2a to 2d. Printing is performed by transferring the printing ink applied on the plate onto the blanket cylinders 3a to 3d, and further onto the sheet paper that is pressed against the blanket cylinders 3a to 3d by the impression cylinders 4a to 4d. It is.

Here, according to Patent Document 2, for example, the swing mechanism is configured as shown in FIG.
In FIG. 5, the swing mechanism 8 of Patent Document 2 grips the leading end of the sheet P supplied from the paper feed table 6a of the paper feed unit 6 to a predetermined stop position, and moves to the claw 6d of the transfer drum 6c. It is configured to deliver.

The swing mechanism 8 includes a swing lever 8b that is swingably supported around a rotation shaft 8a, and a swing claw 8d that is attached to the claw base 8c so as to be openable and closable near the tip of the swing lever 8b. Yes.
The swing claw 8d is supported so as to be swingable around the rotation shaft 8e, and a spring against the cam surface 8h of the cam 8g on which a roller 8f rotatably attached to the side surface of the swing claw 8d is fixedly disposed. It has a configuration that elastically contacts with a tensile force of 8i.

  According to the offset printing machine 1 having such a configuration, the sheet fed from the sheet feeding unit 6 to the transfer cylinder 6c by the swing mechanism 8 with the printing plates attached to the respective plate cylinders 2a to 2d. After P is sequentially printed with the corresponding printing ink in each printing unit 1a to 1c, it is held on its peripheral surface by the claw portions of the intermediate cylinders 5a to 5c and delivered to the next printing unit. Finally, printing is performed by the printing unit 1d, and the paper is discharged onto the paper discharge tray 7c by the paper discharge unit 7 and stacked. Thereby, the printing process is sequentially performed on each sheet.

At that time, each time the sheet P is supplied from the paper feed table 6a of the paper feed unit 6 to a predetermined stop position, the swing lever 8b of the swing mechanism 8 is first driven to rotate by the rotary shaft 8a. When swung to the 6th side, the roller 8f attached to the swing claw 8d rolls along the cam surface 8h of the cam 8g by the tensile force of the spring 8i.
As a result, the swing lever 8b moves to the paper feed unit 6 side based on the shape of the cam surface 8h, and the leading end of the sheet 9 is held between the swing claw 8d and the claw base 8c.

Subsequently, the swing lever 8b is swung in the reverse direction around the rotation shaft 8a, swung toward the transfer drum 6c, and the roller 8f attached to the swing claw 8d is driven by the tension of the spring 8i. Roll along the surface 8h.
As a result, the swing lever 8g moves to the transfer drum 6c side based on the shape of the cam surface 8h, and the swing claw 8d is released away from the claw base 8c, and the leading end of the sandwiched sheet P is passed. Then, the swing lever 8b is again swung toward the paper feed unit 6 side.
The above operation is repeated for each sheet, so that the sheet is fed.
No. 04-015487, Fig. 2

  However, in the conventional offset printing machine 1, as a swing claw opening / closing device for opening / closing the swing claw 8d of the swing mechanism 8, a plate-shaped cam (plate cam) 8g and a cam surface 8h outside the cam 8g are provided. The roller 8f is used as a cam follower that rolls on the swing lever, and the roller 8f attached to the swing claw 8d is elastically biased to the cam surface 8h based on the tensile force of the spring 8i, whereby the swing lever The roller 8f rolls following the shape of the cam surface 8h of the cam 8g with the swing of 8b.

For this reason, when the printing speed of the offset printing press 1 is increased, the roller 8f is less likely to follow the cam surface 8h with respect to the swing speed of the swing lever 8b, and the roller 8f is lifted from the cam surface 8h or the cam surface 8h. Depending on the shape, the phenomenon that the roller 8f jumps from the cam surface 8h has occurred.
As a result, the swing mechanism 8 may not be able to reliably deliver the sheet from the paper supply unit 6 to the transfer cylinder 6c, and there is a problem in that printing efficiency decreases.

  The present invention has been made in view of the above problems. Even when the printing speed is increased with a simple configuration, the sheet is reliably transferred from the sheet feeding unit to the transfer cylinder via the swing mechanism. An object of the present invention is to provide an offset printing machine in which paper feeding is performed.

  In order to solve the above-mentioned problem, an invention according to claim 1 of the present invention is an offset printing machine including a swing mechanism that supplies a sheet to a transfer drum from a paper feed unit, wherein the swing mechanism includes the paper feed. A swing lever that swings to grip the leading edge of the sheet supplied from the section and delivers the sheet to the transfer cylinder, and pivots near the leading end of the swing lever according to the swing of the swing lever. A swing claw opening and closing device comprising a cam and a roller for opening and closing the supported swing claw with respect to a claw base fixed to the tip of the swing lever, and the cam is on one side of the swing shaft of the swing lever It is characterized by being formed as a groove cam that is open to the surface.

  According to a second aspect of the present invention, in the first aspect of the present invention, the roller includes a first roller that contacts the inner cam surface of the grooved cam and a second roller that contacts the outer cam surface. It is characterized by being.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the inner cam surface is disposed so as to be shifted in the axial direction of the swing lever with respect to the outer cam surface.

  According to the present invention having the above-described configuration, when the sheet is supplied from the paper feeding unit to a predetermined position, the swing lever of the swing mechanism swings toward the paper feeding unit, The leading edge of the sheet enters between the claw base and the swing claw is closed with respect to the claw base by the swing claw opening / closing device, so that the front end of the sheet is gripped by the swing claw of the swing mechanism. . Next, when the swing lever of the swing mechanism is swung in the reverse direction and swung toward the transfer drum side, the swing claw is released away from the claw base by the swing claw opening / closing device, so that the front end of the sheet is It is released from the swing claw and delivered to the claw portion of the transfer drum. In this case, since the cam of the swing claw opening / closing device is formed as a groove cam, the rollers constituting the swing claw opening / closing device abut against the inner cam surface and the outer cam surface forming the cam groove when rolling. Will be in touch.

Therefore, if the printing speed becomes high and the roller that rolls on the inner cam surface rises from the cam surface or jumps with the swing of the swing lever, the roller will move to the outer side on the opposite side. By coming into contact with the cam surface, the separation of the roller from the cam surface can be suppressed. As a result, the roller reliably rolls on the cam surface as the swing lever swings, and the swing pawl is reliably opened and closed according to the swing angle of the swing lever.
In this way, even when the printing speed of the offset printing machine is increased, the swing mechanism can reliably deliver the sheet from the sheet feeding unit to the transfer cylinder, and a decrease in printing efficiency can be prevented. .

In addition, the roller in the swing claw opening / closing device is composed of a first roller that contacts the inner cam surface of the groove cam and a second roller that contacts the outer cam surface. Further, the first roller rolls on the inner cam surface, and the second roller rolls on the outer cam surface.
Therefore, when the first roller is lifted from the inner cam surface, the second roller contacts the outer cam surface, and the first roller contacts the outer cam surface and suddenly reversely rotates. The swing lever can be swung smoothly.

Furthermore, the inner cam surface of the swing claw opening / closing device is displaced with respect to the outer cam surface with respect to the axial direction of the swing lever, so that the first roller and the second roller are also displaced from each other in the axial direction. Therefore, both rollers are arranged on the same radius of the swing lever.
Therefore, since the inner cam surface and the outer cam surface are in the same phase with respect to the swing angle of the swing lever, the shape can be simplified and can be easily created.

  Thus, according to the present invention, even when the printing speed of the offset printing machine is increased, the swing pawl can be reliably opened and closed without the roller of the swing mechanism being separated from the cam surface. Therefore, the swing mechanism can reliably deliver the sheet from the sheet feeding unit to the transfer cylinder, and the effect of preventing a decrease in printing efficiency can be obtained.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an offset printing machine according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an enlarged view showing a configuration of a swing mechanism which is a main part of an embodiment of an offset printing machine according to the present invention.
In FIG. 1, the swing mechanism 10 includes a swing lever 11, a claw base 12, a swing claw 13, and a swing claw opening / closing device 20.

  The swing lever 11 is supported so as to be swingable around the rotation shaft 11a, and operates so as to repeatedly swing back and forth between the paper feed unit side and the transfer drum 14 side by a swing mechanism.

The claw base 12 is fixed to the swing lever 11 so that the outer surface is exposed radially outward.
The swing claw 13 is pivotally supported around the swing shaft 13a in the vicinity of the tip of the swing lever 11, and has a radius with respect to the outer surface of the claw base 12 by a swing claw opening / closing device 20 described later. It opens and closes so as to sandwich the sheet from the outside in the direction. Further, the swing claw 13 is urged by a spring 13b.

  The swing claw opening / closing device 20 includes a cam 21 fixedly arranged and a pair of first rollers 22 and second rollers 23 provided on the swing claw 13.

The cam 21 in the present invention described above is configured as a groove cam as shown in detail in FIGS.
Specifically, the cam 21 includes an inner cam surface 21a having the same shape as the outer cam surface 8h of the plate cam 8g in the conventional swing mechanism 8 shown in FIG. 5, and an outer cam surface 21b arranged on the outer side. The groove defined by the inner cam surface 21a and the outer cam surface 21b is open to one side of the swing lever 11 (the front side in FIG. 1).
Here, the shape of the outer cam surface 21b is selected so as to define substantially the same width with respect to the inner cam surface 21a, and as shown in FIG. 3, the inner cam surface 21a is formed of the outer cam surface 21b. Are displaced in the axial direction.

The first roller 22 contacts the inner cam surface 21 a of the cam 21 and the second roller 23 contacts the outer cam surface 21 b of the cam 21.
The first roller 22 and the second roller 23 are attached to the swing claw 13 so as to be rotatable.
Here, as described above, when the swing claw 13 is urged counterclockwise in FIG. 1 by the spring 13b, the first roller 22 comes into contact with the inner cam surface 21a of the cam 21. Yes.

The offset printing press according to the embodiment of the present invention is configured as described above. When printing is performed, the sheet P is supplied from the paper feed table of the paper feed unit to a predetermined stop position as shown in FIG. When this is done, the swing lever 11 is swung to the paper feed unit side, and the first roller 22 and the second roller 23 of the swing claw opening / closing device 20 are moved along the inner cam surface 21a and the outer cam surface of the cam 21 with this swing. By rolling on 21b, the swing claw 13 is separated from the claw base 12 and opened based on the shape of each cam surface. Accordingly, the sheet P is relatively inserted between the swing claw 13 and the claw base 12.
Then, the rollers 22 and 23 of the swing claw opening / closing device 20 roll on the inner cam surface 21a and the outer cam surface 21b of the cam 21 so that the swing claw 13 is closed with respect to the claw base 12, whereby the swing mechanism 10, the leading edge of the sheet P is gripped.

  Next, when the swing lever 11 of the swing mechanism 10 is swung in the reverse direction and swung to the transfer drum 14 side, the rollers 22 and 23 of the swing claw opening / closing device 20 are moved to the inner cam surface 21a of the cam 21 and the outer Rolling on the cam surface 21b, the swing claw 13 is released from the claw base 12 and released. As a result, the leading edge of the sheet P is released from the swing claw opening / closing device 20 and delivered to the claw portion 14a of the transfer cylinder 14, and is passed through the transfer cylinder 14 to the impression cylinder 15 (shown by a chain line) of the first printing unit. Then, printing on the sheet P is performed.

  In this case, since the cam 21 in the swing claw opening / closing device 20 of the swing mechanism 10 is configured as a groove cam, the swing speed of the swing lever 11 of the swing mechanism 10 is increased by increasing the printing speed of the offset printing press. In this case, even if either the first roller 22 or the second roller 23 of the swing claw opening / closing device 20 is lifted from the inner cam surface 21a or the outer cam surface 21b of the cam 21, the other roller is placed on the cam surface. The contact between the first roller 22 and the second roller 23 is always in contact with the inner cam surface 21 a or the outer cam surface 21 b of the cam 21.

  Therefore, when the first roller 22 and the second roller 23 always forcibly roll following the shapes of the inner cam surface 21a and the outer cam surface 21b of the cam 21, the swing pawl 13 always has a predetermined opening / closing operation. Thus, the leading edge of the sheet P can be reliably conveyed from the predetermined stop position supplied from the paper feed table of the paper feed unit to the delivery position to the transfer cylinder 14.

  Thus, even if the printing speed of the offset printing machine is increased, the swing claw 13 can be reliably opened and closed by the swing claw opening / closing device 20 of the swing mechanism 10 in accordance with the swing position of the swing lever 11. The sheet P is surely delivered to the transfer cylinder 14.

In the embodiment described above, the swing mechanism 10 has the pair of first rollers 22 and second rollers 23 with respect to the groove cam 21, but is not limited thereto, and may be a single roller. In this case, the roller is normally in contact with the inner cam surface 21a of the groove cam 21, but when the roller is about to lift from the inner cam surface 21a, the roller is lifted by contacting the outer cam surface 21b. Can be suppressed.
In the above-described embodiment, the widths of the inner cam surface 21a and the outer cam surface 21b of the cam 21 are selected to be substantially constant, but the shapes of the inner cam surface 21a and the outer cam surface 21b are different from each other. Thus, it is possible to individually set the open / close state of the swing pawl in a reciprocating manner when the swing lever 11 is swung.
Furthermore, in the above-described embodiment, the offset printing machine performs four-color printing on one side of the sheet, but is not limited thereto, and is not limited to this, but is performed in a single-color printing, a two-color printing, a three-color printing, or five colors or more. Needless to say, the present invention can be applied to an offset printing machine that performs multi-color printing or double-sided printing.
In this way, according to the present invention, even with a simple configuration, even if the printing speed is increased, the paper feeding unit can reliably feed the paper to the transfer cylinder via the swing mechanism. An offset printing machine can be provided.

It is an enlarged view which shows the structure of the swing mechanism which is the principal part of one Embodiment of the offset printing machine by this invention. It is an enlarged plan view which shows the cam in a swing mechanism. It is sectional drawing of a cam. It is a schematic sectional drawing which shows the whole structure of the conventional offset printing machine. It is a schematic sectional drawing which shows the structure of the conventional swing mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Swing mechanism 11 Swing lever 11a Rotating shaft 12 Claw base 13 Swing claw 13a Oscillating shaft 13b Spring 14 Transfer cylinder 14a Claw part 15 Pressure cylinder 20 Swing claw opening / closing device 21 Cam (groove cam)
21a Inner cam surface 21b Outer cam surface 22 First roller 23 Second roller P Sheet

Claims (3)

In an offset printing machine having a swing mechanism for supplying a sheet from a sheet feeding unit to a transfer cylinder,
The swing mechanism includes a swing lever that swings to grip a leading edge of a sheet supplied from the sheet feeding unit and delivers the sheet to the transfer cylinder, and according to the swing of the swing lever A swing claw opening / closing device comprising a cam and a roller for opening and closing a swing claw pivotally supported near the tip of the swing lever with respect to a claw base fixed to the tip of the swing lever,
The offset printing machine according to claim 1, wherein the cam is formed as a groove cam that opens to one side of a swing shaft of the swing lever.   2. The offset printing press according to claim 1, wherein the roller includes a first roller that contacts the inner cam surface of the groove cam and a second roller that contacts the outer cam surface. .   The offset printing press according to claim 1 or 2, wherein the inner cam surface is arranged so as to be shifted in an axial direction of the swing lever with respect to the outer cam surface.

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