JPH0655502B2 - Paper edge tension device of sheet-fed printing machine with reversing mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is a sheet-fed printing machine with a reversing mechanism, in which the paper tail that is adsorbed by an adsorption head during double-sided printing is pulled up and down in the left-right direction and tensioned. It relates to the device.

[Prior Art] With the diversification of printing, various sheet-fed printing machines with a reversing mechanism that can be used for single-sided printing and double-sided printing have been proposed and put into practical use. Are roughly classified into a single-type one having a double diameter reversing cylinder as a reversing cylinder, and a three-type one having a transfer cylinder and a reversing cylinder and a double-diameter cylinder therebetween.

In the double-diameter cylinder of these three types, a gripper device (hereinafter referred to as a claw) composed of a claw and a claw base is arranged in parallel in the axial direction at a position that divides the outer peripheral portion into two parts in the circumferential direction. Similarly, two rows of suction heads are provided at positions such that the outer peripheral portion is equally divided into two rows, the suction heads having a different phase in the circumferential direction from the claws.

And in the case of single-sided printing, the paper printed with the first color is
The nails of the transfer cylinder are gripped by the double-diameter cylinder and conveyed while being attached to the double-diameter cylinder. Further, the grips of the reversing cylinder are gripped and conveyed, and then the second color is printed. In such single-sided printing, the paper that is conveyed with its tip being held by the claw of the double-diameter cylinder is conveyed by being attracted to the bottom of the paper by the suction head so that the non-holding part other than the gripping edge does not flap. It

In the case of double-sided printing, the printed paper on the front side is gripped from the claw of the transfer cylinder to the claw of the double-diameter cylinder in the same way as in single-sided printing, and then transported to the claw of the reversing cylinder. It is changed and transported. In this case, the double-diameter cylinder rotates more than the length in the top-bottom direction of the paper than in the case of single-sided printing, and the claws of the reversing cylinder carry the paper by holding the bottom of the paper, and as a result, the paper is reversed and the next printing is performed. In the unit, the back side of the paper is printed to make double-sided printing. Even in the case of such double-sided printing, the paper that is conveyed with the tip held by the claw of the double-diameter cylinder is sucked at the bottom of the paper by the suction head to prevent the non-holding part other than the gripping edge from fluttering. While being conveyed, when the gripper of the reversing cylinder is changed to the nail, the suction head sucks the paper tail until the nail finishes gripping the paper tail, and the gripping is ensured.

In double-sided printing by such a sheet-fed printing press with a reversing mechanism, the paper tail adsorbed by the suction head is slacken in the vertical direction or the left-right direction when the gripping head of the double-diameter cylinder is changed to the nail of the reversing cylinder. Since printing misregistration occurs when printing on the back surface and a printing failure occurs, various paper tail tensioning devices for tensioning the paper attracted by the adsorption head have been conventionally proposed.

[Problems to be solved by the invention]

However, the conventional paper tail tensioning device has the following problems. That is, for example, Japanese Patent Publication No. 44-
No. 9056 discloses a fan-shaped side plate for holding all suction heads, which is rotated about a double-diameter cylinder axis until it hits a stopper to extend the wrinkles of the paper. Since the wrinkles are stretched only in one direction, the paper may sag to the left and right, and it is not possible to completely eliminate print registration defects.

Also, for example, in the one disclosed in Japanese Patent Publication No. 54-30323, each suction head is rotatably supported, its suction port is eccentric with respect to the rotation center, and the suction head is rotated together by a cam mechanism. By doing so, the suction port is eccentrically moved and the paper is tense in the vertical direction and the left and right direction.
Not only does the position of the bottom of the paper become unstable, which causes printing misregistration, but also troublesome refueling of the cam is required. In addition, the number of parts is too large to provide at low cost.

[Means for solving problems]

In order to solve such a problem, in the present invention, each suction head of the double-diameter cylinder is attached to a piston rod of an air cylinder that moves in a direction inclined with respect to the circumferential direction of the double-diameter cylinder, and The suction air passage was provided through the axial center of the piston rod.

[Operation] The trailing edge of the paper that is conveyed from the transfer cylinder's claw to the double-diameter cylinder's claw is sucked by the suction head until it is gripped by the reversing cylinder's claw. Since the piston rod of is moved in an oblique direction, the suction head attached thereto moves in an oblique direction while adsorbing the paper tail, and the paper tail is pulled in the vertical direction and the left-right direction.

〔Example〕

1 to 4 show an embodiment of a paper tail tensioning device according to the present invention. FIG. 1 is a longitudinal sectional view thereof, FIG. 2 is a plan view thereof, and FIG. Schematic plan view of the fourth
The figure is a cylinder arrangement diagram of a sheet-fed printing press with a reversing mechanism shown for explaining a double-sided printing operation. In the figure, an impression cylinder 5 having a gripper device 4 (hereinafter, referred to as a claw 4) composed of a claw 2 and a claw base 3 in an outer peripheral cutout is provided obliquely below the blanket cylinder 1 facing the plate cylinder. A blanket cylinder 6 that is provided with the surfaces facing each other and that also contacts the plate cylinder in the downstream printing unit, and a gripper device 9 (hereinafter, referred to as a claw 9) including a claw 7 and a claw base 8. An impression cylinder 10 whose peripheral surface is in contact with the blanket cylinder 6 is provided. A transfer cylinder 11, a double-diameter cylinder 12, and a reversing cylinder 13 whose circumferential surfaces are in contact with each other are provided between the two impression cylinders 5 and 10.
Is provided with a reversing mechanism including three rollers. Of these, the transfer drum 11 is provided with a gripper device 16 (hereinafter, referred to as a claw 16) including a claw 14 and a claw base 15 in an outer peripheral cutout. Further, the double-diameter cylinder 12 has a double diameter of the transfer cylinder 11 and the like, and at a position where the outer peripheral portion thereof is divided into two equal parts, two sets of gripper claw devices 19, 20 (including a claw 17 and a claw base 18) are provided. (Hereinafter, referred to as claws 19 and 20), each claw 19,
Two rows of suction heads 43, which will be described later, are arranged at a position ahead of 20 by a predetermined angle in the body rotation direction. The structure of the double diameter cylinder 12 will be described later in detail. In addition, the reversing body 13
In the outer peripheral notch, a gripper device (A) 25 composed of a claw 23 and a claw base 24 (hereinafter referred to as a claw (A) 25) and a gripper device (B) composed of a claw 26 and a claw base 27. ) 28 (hereinafter referred to as claw (B) 28) are arranged adjacent to each other in the circumferential direction.

The double-diameter cylinder 12 includes a cylinder main body 29 having a casting space portion,
It is formed of side plates 30 on both sides which are joined to both end faces thereof and fixed to be rotatable and adjustable, and end shaft portions at both ends of the body 29 are pivotally supported by the frames on both sides. Side plates 30 on both sides
A pair of intake pipes 31, 32 are rotatably supported at a position where the outer peripheral portion of the intake pipe is bisected in the circumferential direction.
The reference numeral 32 is connected to a vacuum pump as an air source via a rotary valve (not shown). On the other hand, on the outer peripheral wall of the body 29, a plurality of grooves 33 having a predetermined circumferential angle are provided in parallel in the axial direction, and an air cylinder 34 is provided in each groove 33. , 32 supported by air pipes 35 and 36 fixedly attached thereto. The air cylinder 34 includes a cylinder 37 having a bottomed cylindrical shape and a piston rod 38 with a head that is fitted in an inner hole of the cylinder 37 so as to move forward and backward. An air passage 38a, one end of which is closed by a washer 39 by bolting, and a pair of air holes 38b formed from the peripheral surface of the head are provided. The air passage 38a
The side opposite to the washer 39 has a blind shape. 40 is fitted on the washer 39 side protrusion of the piston rod 38
9 is a suction base fixed by bolting, and is prevented from rotating by a pin 41 that is engaged with a U-shaped groove at the lower end and screwed into a screw hole of the cylinder 37. 42 is bolted with its upper end surface slightly protruding from the body circumferential surface. Thus, the suction port 42 and the suction platform 40 that form the suction head 43 are provided with an intake passage 44 that opens to the upper end surface, and the intake passage 44 communicates with the air passage 38a. The air pipes 35, 36 are respectively screwed into a port 45 provided in communication with the air hole 38b and a port 46 provided in communication with the rod end chamber of the air cylinder 34. A compression coil spring 47 is interposed in the rod end chamber to bias the piston rod 38 to the side opposite to the suction head. By doing this, both ports 45,
When the suction air pressure is simultaneously applied to 46, the atmosphere outside the suction port 42 causes the intake passage 44, the air passage 38a, and the air hole 38 to flow.
While being sucked from the port 45 via b, the pressure inside the rod end chamber of the air cylinder 34 is reduced, and the suction head 4
3 moves diagonally.

The double-sided printing operation by the sheet-fed printing machine with the reversing mechanism having the double-diameter cylinder configured as described above will be described. When each cylinder rotates in the direction shown by the arrow in FIG. 4, the paper 50, which has been gripped by the pawl 4 of the impression cylinder 5 from the paper feeding device through the swing device, is gripped by the pawl 16 of the transfer cylinder 11 again. This paper 50 is conveyed, and when it passes between the blanket cylinder 1 and the impression cylinder 5, the first color is printed on the surface. The paper 50 is conveyed while being gripped by the claw 16 of the transfer cylinder 11 to the claw 19 (20) of the double-diameter cylinder 12, and suction air acts on the port 45 due to the timing regulation of the rotary valve during the conveyance. Since the atmosphere outside the suction port 42 is sucked, the paper tail is adsorbed to the suction port 42. Due to the timing regulation of the rotary valve, the port 46 is slightly delayed after the start of the adsorption.
Since suction air acts on the rod end chamber of the air cylinder 34 to reduce the pressure, the piston rod 38 moves diagonally to the suction head 43 side against the elastic force of the compression coil spring 47, and the paper being sucked is absorbed. By pulling the butt diagonally away from the grip edge, the butt becomes tense in the vertical direction and the horizontal direction at the same time. When the paper 50 thus tensioned is conveyed until the bottom of the paper reaches the opposite contact points of the drums 12 and 13 as indicated by reference numeral 50A in the figure, the claw (B) 28 closes and grips the bottom of the paper and sucks it. Since the head 43 releases the paper tail from adsorption, the paper 50A is conveyed by the reversing cylinder 13 with the paper tail side ahead. Since the paper 50A is tense in the top-bottom direction and the left-right direction at the time of gripping the tail of the paper, the nail (B) 28 grips the correct part. Then, while the nail (B) 28 is being conveyed by the grip, both the nails (A) 25 and (B) 28 are opened and closed with a timing difference for a moment, and the paper 50A is changed from the nail (B) 28 to the nail (A) 25. It is changed and transported. When the claw (A) 25 and the claw 9 of the impression cylinder 10 face each other, the paper 50A
Is gripped by the claw 9 and conveyed as indicated by reference numeral 50B in the figure. The back surface of the paper 50B contacts the blanket cylinder 6 when passing between the blanket cylinder 6 and the impression cylinder 10, so that the back surface is printed, and the front surface is printed to be double-sided.
At the time of printing on the back surface, since the paper 50A is properly gripped by the nail (B) 28 in a state in which the paper 50A is tense in the up-down direction and the left-right direction, print registration failure does not occur.

In the present embodiment, the rod end chamber of the air cylinder 34 is decompressed in order to move the suction head 43. However, a head end chamber is provided in the air cylinder 34 and pressurized air is sent to pressurize the head end chamber. You may do it.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, in the sheet-fed printing press with the reversing mechanism, each suction head of the double-diameter cylinder is moved in the direction inclined with respect to the circumferential direction of the double-diameter cylinder. Since it is attached to the piston rod of, the paper that is gripped and conveyed by the double-diameter cylinder is sucked by the suction head from the middle of the conveyance until it is gripped by the claw of the reversing cylinder. By moving the suction head diagonally, the paper is pulled diagonally and tensioned in both left and right directions, and the correct position can be gripped, so that print registration defects do not occur in subsequent printing, and the quality of the printed material is greatly improved. Improve to. And, by using the air cylinder as the tension device for the paper tail, the number of parts is reduced, the cost is reduced, the damage of the parts is reduced, the maintenance is easy, the inertia is small, and the overall weight is light. Can be measured.

Further, since the suction air passage of the suction head is provided so as to penetrate the axial center of the piston rod, the piston rod can also be used as the suction air passage of the suction head, so there is no need to separately provide a pipe as the suction air passage, For this reason,
Since the number of parts is reduced and there is no member that moves with the movement of the piston rod, not only can the device be made compact, but it also has few failures and excellent durability.

[Brief description of drawings]

1 to 4 show an embodiment of a paper edge tensioning device of a sheet-fed printing press with a reversing mechanism according to the present invention. FIG. 1 is a longitudinal sectional view thereof, FIG. 2 is a plan view thereof, and FIG. FIG. 4 is a schematic plan view of a double-diameter cylinder in which this is performed, and FIG. 4 is a cylinder arrangement diagram of a sheet-fed printing press with a reversing mechanism shown for explaining a double-sided printing operation. 12 ... Double diameter cylinder, 31, 32 ... Intake pipe, 34 ... Air cylinder, 35, 36 ... Air pipe, 38 ... Piston rod, 38a ... Air passage, 42 ... Suction port, 43 ... Adsorption Head, 44 ... Intake passage, 45, 46 ... Port,
50, 50A, 50B ... Paper.

Claims (1)

[Claims] 1. A sheet-fed printing machine with a reversing mechanism, comprising a plurality of suction heads for sucking paper tails, which have suction openings that open on the peripheral surface of a double-diameter cylinder, and are arranged in parallel in the axial direction at the peripheral portion of the cylinder. The suction head is attached to a piston rod of an air cylinder that moves in a direction inclined with respect to the circumferential direction of the double-diameter cylinder, and a suction air passage of the suction head is provided so as to penetrate the axial center of the piston rod. A paper edge tension device for a sheet-fed printing press with a reversing mechanism, which is characterized in that