JPH10109404A - Sheet guide for sheet-fed press - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly, accurately and stably transfer a sheet by providing a plurality of air emitting nozzles to the surface of an air duct regardless of the thickness of the sheet to be handled and opposing air emitting nozzles back to back across the central part of a machine to open the nozzles toward both width ends. SOLUTION: A plurality of air emitting nozzles 8a, 8b emitting air toward both side ends of the sheet 7 across the center in the lateral width direction of a printer being the center of the running sheet 7 are provided to the upper surface of an air duct 6. An air supply means is provided corresponding to the air emitting nozzles 8a, 8b so as to be positioned at the middle bottom part of the air duck 6 and air circulating ducks 9 are arranged along both side parts and bottom part of the air duct 6. Both of thin paper and thick paper can be transferred to the rear end of the sheet 7 by the action of the air streams formed to the upper surface of the air duct 6 without damaging the sheet and, in addition, wrinkles easy to generate on a paper surface especially in the case of thin paper by the air streams toward both width ends of the sheet 7 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor printing sheet-fed printing press in which a plurality of sets of printing apparatuses having different ink colors are juxtaposed.

[0002]

2. Description of the Related Art A conventional device will be described with reference to FIGS.

FIGS. 9 and 10 are explanatory views of the structure of an intermediate cylinder (or a paper discharge shaft) provided in a sheet-fed printing press. FIG. 9 is a skeleton for thick paper (0.2 to 0.8 m / m). FIG. 10 shows an arc-shaped cylinder for thin paper (0.04-0.6 m / m).
FIG. 11 is an explanatory diagram showing a schematic configuration of a sheet-fed printing press and a sheet path.

As shown in FIG. 11, a sheet-fed printing press includes a paper feed unit (19) and a plurality of sets of printing devices (2) as main components.
a), (2b), (2c), and (2d), and a paper discharge unit (4). The sheets (7) stacked on the table of the sheet feeding section (19) are separated one by one from the uppermost layer, sent out through a conveyor (20), and then transferred to a swing gripper (21). Then, it is sent to the middle between the blanket cylinder (22a) and the impression cylinder (23a), and the first color printing is performed.

Sheet (7) for which printing of the first color has been completed
Is carried out between the blanket cylinder (22a) and the impression cylinder (23a), and is transferred to the intermediate cylinder (also referred to as a sheet feeding cylinder) (3a).
And an impression cylinder (23b) for printing the second color of the next process from the intermediate cylinder (3a) together with the blanket cylinder (22b).
Handed over to

Thereafter, printing is sequentially performed, and the sheet (7) sent out between the blanket cylinder (22d) and the impression cylinder (23d) for performing printing at the final stage is delivered to the paper discharge shaft (5). Subsequently, the paper is transferred from the paper discharge shaft (5) to the chain conveyor (24) and transferred to the paper discharge part (4), where the paper discharge part (4) is provided.
Will be sequentially stacked on the table. (25) in the figure
Is a sheet guide for guiding a sheet passed from the impression cylinder (23) to the intermediate cylinder (18) or the skeleton cylinder (11).

By the way, a sheet (7) to be printed in a normal sheet-fed printing press is formed from thin paper of about 0.04 m / m to 0.1 m / m.
A thick paper of about 8 m / m is used, and sometimes a highly rigid sheet made of a metal plate or a synthetic resin is used. Regarding the sheet transfer from the printing apparatus (2) to the next-step printing apparatus (2), generally, the thin paper (7a) has low rigidity and the rear end of the sheet (7a) flaps, or the thick paper (7b) In the case of a sheet having high rigidity such as a sheet or a metal plate, the rear end of the sheet (7b) separates from the impression cylinder (23) and the lower sheet guide (25) due to the centrifugal force caused by the rotational transfer and the reaction force (restoring force) against bending of the sheet itself. )
There is a possibility of crashing into. In other words, paper splash tends to occur.

[0008] The fluttering or splashing of the paper causes stains on the printing surface, breaks or scratches on the sheet, and is a major factor in lowering the quality of the printing paper (7). For this reason, there are two representative types of intermediate cylinder (3), a skeleton cylinder (11) and a cylindrical cylinder (18), and the type most suitable for the rigidity of the frequently used sheet is adopted. It has become.

FIG. 9 illustrates a skeleton type intermediate cylinder (11) mainly applied to a cardboard sheet (7b). The skeleton cylinder (11) of this type is provided at both left and right ends of a printing apparatus (2). A pair of rotating bodies (arms) (26) that are arranged and rotate about the axis (R) are arranged, and extend from the tip of one arm (26) to the corresponding tip of the other arm (26). A plurality of sets of grippers (28) are arranged in parallel on the shaft (27). (Note that the rotation trajectory of the tip of the arm is as shown by the dashed line in the figure.) The skeleton cylinder (11) is engaged with the impression cylinder (2) via the sheet (7).
It is characterized in that the contact area with 3) is as small as possible.
Bending deformation can be performed from the point (P) close to 8).
That is, the close point (P) becomes the point of action, and by increasing the distance from this point to the rear end of the sheet (7), the function of reducing the reaction force for returning the sheet (7) is improved.

[0010] By the above-mentioned function, the paper spring whose rear end impacts against the sheet guide (25) provided below the body (11) can be softened, so that scratches and break deformation can be reduced. ing. However, in the skeleton cylinder (11) of this type, on the contrary, the rear end free area of the sheet (7) to be transported increases, and in the case of the thin paper (7a), the flutter of a larger sheet is generated.

On the other hand, the one illustrated in FIG. 10 is a cylindrical body-type intermediate cylinder (18) mainly applied to a thin paper sheet (7a). The cylindrical body (18) of this type is a roll that rotates around the axis (R), and a plurality of sets of grippers (28) are provided at two corresponding positions in the circumferential direction.
Are juxtaposed.

The cylindrical cylinder (18) is characterized in that the contact area with the impression cylinder (23) engaged via the sheet (7) is increased, and the sheet (7a) to be rotatably transported is not changed. Since the downstream side of (28) is guided along the outer peripheral surface of the cylindrical body (18), the function of reducing the fluttering of the rear end of the sheet (7a) is enhanced.

With the above-described function, it is possible to reduce problems such as wrinkles generated on the rear end side of the sheet and doubles and scratches caused by flapping of the paper. On the other hand, in the case of the cylindrical cylinder (18) of this type, when the thick paper (7b) is conveyed, the free area of the sheet is reduced, so that stronger paper splash is generated.

[0014]

As described above, in the prior art, the state at the time of transfer greatly varies depending on the thickness of the sheet (7) to be printed, that is, the sheet rigidity. Each of the cylinder (3), the skeleton type cylinder (11) and the cylindrical type cylinder (18) employed as the paper discharge shaft (5) is converted from thin paper (7a) to thick paper (7b).
It is not ideal as a method for stably and reliably transferring sheets over the entire area.

It is impossible to replace and replace the intermediate cylinder (3) and the discharge shaft (5) each time according to the specification (rigidity) of the sheet changed by the order change. In this case, the printing operation was performed while leaving scratches and other troubles due to unstable sheet transfer.

Further, the sheet held by the press cylinder on the pawl of the intermediate cylinder is transferred by the intermediate cylinder, but the subsequent sheet on the press cylinder attempts to move along the impression cylinder as it is. FIG.
This indicates that there is a problem that a sheet may collide with the paper guide X.

Accordingly, such various inconveniences are solved, and by improving the intermediate cylinder (3), the paper discharge shaft (5) or the sheet guide (25), the entire area from the thin paper (7a) to the thick paper (7b) is improved. A highly versatile sheet conveying device capable of stably transferring sheets has been strongly desired.

The present invention has been made in response to such needs, and has as its object to provide a transfer means capable of reliably, accurately and stably transferring a sheet regardless of the thickness of the sheet to be handled. It is an issue.

[0019]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problem, and in a multicolor printing sheet-fed printing press, a paper guide provided near an outer periphery of an intermediate cylinder or a discharge shaft is provided by an air duct. A plurality of air discharge nozzles are provided on the surface of the air duct, and the air discharge nozzles provide sheet guides for sheet-fed printing press that open toward both width ends with their backs facing the center of the machine. For example, air compressed by the operation of a fan or other air supply means flows out of the air discharge nozzle, and a predetermined amount of air flowing toward both width ends between the intermediate cylinder or the paper discharge shaft and the air duct surface serving as a sheet guide. When the sheet sucked by the air flow attempts to contact the sheet guide, the trailing edge of the sheet is pushed up by the air pressure, and the sheet moving away from the sheet guide is formed. Is drawn to the paper guide side, thus eliminating both the paper splash that occurred in the case of thick paper and the flapping that occurred in the case of thin paper, and also the generation of wrinkles due to the air flow in the width direction of the sheet to be transported. Therefore, it is possible to obtain a highly stable device that also eliminates various problems such as scratches and dirt on the sheet.

In the present invention, the air discharge nozzle may be arranged such that the air discharge nozzle is turned toward the both ends with the back thereof facing the center of the machine. By providing a sheet guide for a sheet-fed printing press that opens toward an intermediate direction with respect to the upstream direction of the machine, and by opening an air discharge nozzle toward an intermediate direction between both width end directions of the machine and the upstream direction of the printing sheet. After the leading edge of the sheet has moved from the impression cylinder to the intermediate cylinder, the subsequent sheet on the continuous impression cylinder tries to advance along the impression cylinder and hits the sheet guide, pushing up the sheet by the airflow, and the sheet is pushed up. This prevents the vehicle from hitting the seat guide and allows the vehicle to travel properly.

Further, according to the present invention, preferably, a duct having an air intake port is provided at both ends of the air duct, and the duct is connected to an air suction side of air supply means for supplying air to the air duct. Provide sheet guide for leaf printing machine,
The air flowing out of the air discharge nozzle and flowing on the surface of the air duct and reaching both ends is fed back to the air suction side of a fan or a blower or the like through a duct having an air intake port provided therein and circulated. This circulation regulates the reflection of air and the generation of turbulence at the both width ends, thereby contributing to the prevention of flapping of the thick paper and thin paper.

Further, the present invention provides a sheet guide for a sheet-fed printing press, wherein the air discharge nozzle provided on the surface of the air duct is integrated with or separate from the air duct. Depending on the type, it can be integrated with the air duct or a separate type. Especially in the case of the separate type, the discharge condition can be easily modified and improved, and a favorable discharge can be easily obtained. The degree is further expanded.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. 1 and 2
FIG. 3 shows a schematic configuration of a sheet guide for a sheet-fed printing press viewed from a plane and a side, respectively. FIG. 3 is a structural example of an air discharge nozzle provided in the sheet guide, FIG.
5 and 6 relate to an example of the air circulation system, and FIG. 7 relates to the description of the behavior of the sheet.

A sheet guide (1) for a sheet-fed printing press is provided with an intermediate cylinder (3) located between the printing device (2) and the printing device (2), or a most downstream printing device (2) and a discharge unit. (4)
An air duct (6) is provided as a sheet guide (1) disposed close to the outer periphery of a paper discharge shaft (5) disposed in the middle of the air duct (5). ), That is, a plurality of air discharge nozzles (8) for discharging air toward both ends with respect to the center in the width direction of the printing apparatus (2).

An air supply means is provided at the middle bottom of the air duct (6) and corresponds to the air discharge nozzle (8). (9) in the figure is an air duct (6)
Are air circulation ducts arranged along both sides and the bottom.

In the present embodiment, a part of the upper surface of the air duct (6) is used as an air discharge nozzle (8) in a shear deformation method, a method using a fan (10) as an air supply means, and a sheet. A method employing a skeleton type body (11) as a transfer means is illustrated.

The air discharge nozzle (8) needs to form an ideal air flow corresponding to the sheet (7) to be conveyed. As shown in FIG. 3, the air discharge nozzle (8) is separately provided. It is preferable to select one that has been manufactured and has a good discharge flow by a method of fixing it to a hole formed in the upper surface of the air duct (6).

3A has a small air stagnation portion (12) in the air discharge nozzle (8) as shown by a broken line, and extends along the upper surface of the air duct (6). A flow path (vent) (13) having a predetermined inclination angle capable of discharging the discharged air is provided, and the one shown in (b) of FIG. A flow path (vent) having a predetermined inclination angle so that it can pass through at a stretch
(13) is provided, and the inclination angle of the hole diameter of the flow path is set in consideration of various conditions such as a sheet conveying speed, a sheet thickness, an air supply amount, and an air pressure.

FIG. 5 shows an example of the air circulation supply system.
And those illustrated in FIG. 5 is a system in which a fan (10) is provided at the bottom of the air duct (6) and corresponding to the air discharge nozzle (8), as in FIG. Alternatively, a method is provided in which a blower (14) is provided, and air can be supplied to an air discharge nozzle (8) on the upper surface of the air duct (6) via an air pipe (15) and a branch pipe (16). In the drawing, (17) is a valve for controlling the air supply amount.

In both types shown in FIGS. 5 and 6, the air discharged from the air discharge nozzle (8) and flowing out along the upper surface of the air duct (6) is sucked and collected from both ends of the air circulation duct (9). , The fan (10) or the blower (14) is fed back to the air suction side of the air supply means.

Since the present embodiment is configured as described above, the air of a predetermined pressure sent from the air supply means such as the fan (10) or the blower (14) is supplied to the air duct (6) with the width of the upper surface. Air is discharged to both sides in the width direction via air discharge nozzles (8a) and (8b) disposed on both sides of the center of the direction to form an air flow (layer) on each side.

The air that has flowed out to both width ends is sucked into the air circulation duct (9) and is again supplied to the air supply means (10).
Alternatively, the air is fed back to the air intake of (14), and the air circulation is repeated continuously thereafter.

The air flow formed on the upper surface of the air duct (6) acts as follows according to Bernoulli's theorem. That is, as shown in FIG.
Paper (7a) whose sheet trailing edge flaps due to the rotational transfer of
In the case of (1), the air duct (6) is depressurized by the air flow and drawn to the surface side, and is suspended and supported with a predetermined gap from the surface.

Further, the rigidity is high and the rear end of the sheet comes into contact with the surface of the air duct (6). In other words, in the case of thick paper (7b) or the like which causes paper splash, the air duct (6)
Is pushed back from the surface side, and is floated and supported with a predetermined gap from the surface.

In this manner, the thin paper (7a) or the thick paper (7b) can be transferred to the rear end of the sheet (7) without being damaged by the action of the air flow formed on the upper surface of the air duct (6). In addition, the air flow in the width direction of both ends of the sheet (7) also has an effect of preventing wrinkles that easily occur on the paper surface, especially in the case of thin paper (7a).

The sheet guide (1) according to the present embodiment is constructed and functions as described above, and is the same as the intermediate cylinder (3) or the paper discharge shaft (5), for example, the skeleton cylinder ( 11) with thin paper (7a) (0.04m /
m) to thick paper (7b) (0.8 m / m), and various sheets (7) having a thickness ranging from 0.8 to 0.8 m / m.

It goes without saying that various methods other than those exemplified above can be adopted for the control method such as the shape and direction of the air discharge nozzle (8), the increase / decrease of the air supply amount, and the supply timing.

Next, a second embodiment of the present invention will be described with reference to FIG.
It will be described based on. In the drawings, the same parts as those of the above-described conventional device and the first embodiment are denoted by the same reference numerals, and overlapping description will be omitted.

That is, in the present embodiment, the air discharge nozzles (8c) and (8d) are arranged such that one group and the other group are in different directions with respect to the center of the machine, and each of the two groups is different. The opening is directed toward an intermediate direction between the width end direction and the upstream direction of the printing sheet.

In the prior art described above, after the leading end of the printing sheet (7) is transferred from the impression cylinder (23) to the intermediate cylinder (3) as shown in FIG. (7) is trying to go along the impression cylinder (23), and there is a problem that the sheet guide is hit by the X portion.
In the present embodiment, since the air discharge nozzles (8c) and (8d) are opened in the above-described directions, the air flow discharged by the discharge nozzles has the effect of extending the wrinkles of the sheet in the width direction, and As shown in FIG. 7, it is possible to prevent the sheet from hitting the sheet guide (6) in the X section by the discharge pressure.

Although the present invention has been described with reference to the illustrated embodiments, the present invention is not limited to such embodiments.
It goes without saying that various changes may be made to the specific structure within the scope of the present invention.

[0042]

As described above, according to the present invention, when thick paper is used as printing paper due to the action of the air flow discharged from the air duct which is provided along the outer periphery of the intermediate cylinder or the paper discharge shaft with a predetermined gap. In addition to buffering the paper splash at the trailing edge of the sheet to prevent scratches, it can also buffer the fluttering of the sheet's trailing edge that occurred when thin paper was used as printing paper, suppressing double filing and scratching, and stabilizing Thus, a highly reliable device can be obtained.

According to the second aspect of the present invention, the sheet is transferred from the impression cylinder to the intermediate cylinder by discharging the airflow in an intermediate direction between both widthwise ends of the machine and the upstream direction of the printing sheet. The rear part of the sheet can be prevented from colliding with the sheet guide, the risk of damage to the sheet is greatly reduced, and it is stable from thin paper to thick paper (0.04 to 0.8 m / m). This makes it possible to transfer a printed sheet, greatly improve versatility, and achieve high-speed printing and high quality without scratches and stains on the sheet.

According to the third aspect of the present invention, the air discharged from the air discharge nozzle is collected by the ducts at both end portions and circulated to the suction side of the air supply means. It suppresses the reflection of air, the generation of turbulence, etc., and greatly contributes to the prevention of the occurrence of heavy paper springs and the fluttering of thin paper.

According to the fourth aspect of the present invention, the air discharge nozzle is not only integrally formed with the air duct, but also
Since it is possible to adopt a separate configuration, it is possible to appropriately select and adopt a preferred shape according to the situation, and to increase the degree of freedom to follow a situation change.

[Brief description of the drawings]

FIG. 1 shows a schematic configuration of a sheet guide for a sheet-fed printing press according to a first embodiment of the present invention, wherein (a) is a plan view and (b).
FIG. 3 is a view taken along the line AA in FIG.

FIG. 2 is a side view showing a schematic configuration of a sheet guide for a sheet-fed printing press according to the first embodiment.

FIGS. 3 (a) and 3 (b) are diagrams for explaining the structure of an air discharge nozzle employed in the first embodiment of the present invention, which are different from each other. FIGS.

FIGS. 4A and 4B illustrate the function of a paper guide used in the first embodiment of the present invention, wherein FIG. 4A shows the relationship between a sheet and an air duct, FIG. 4B shows a vertical section of the air duct, and FIG. Explanatory drawing which shows the cross section of an air duct.

FIG. 5 is an explanatory diagram of an air circulation system employed in the first embodiment.

FIG. 6 is an explanatory diagram of an air circulation system of a type different from that of FIG. 5 employed in the first embodiment.

FIG. 7 is an explanatory diagram of a behavior of a sheet according to the first embodiment.

8A and 8B show a schematic configuration of a sheet guide for a sheet-fed printing press according to a second embodiment of the present invention, wherein FIG. 8A is a plan view and FIG.
(A) is a view on arrow B-B of FIG.

FIG. 9 is an explanatory view showing a part of a sheet transfer section of a conventional sheet-fed printing press and a sheet guide for thick paper.

FIG. 10 is an explanatory view showing a part of a sheet transfer section of a conventional sheet-fed printing press and a sheet guide for thin paper.

FIG. 11 is an explanatory view of a behavior of a sheet in the conventional sheet guide of FIG. 9;

FIG. 12 is an explanatory diagram illustrating a schematic configuration of a sheet-fed printing press and a flow of sheets.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sheet guide 2 Printing device 3 Intermediate cylinder 4 Discharge part 5 Discharge shaft 6 Air duct 7 Sheet 8 Air discharge nozzle 9 Air circulation duct 10 Fan 11 Skeleton cylinder 12 Air retention part 13 Air flow path (vent) 14 Blower 15 Air pipe 16 Branch pipe 17 Valve 18 Cylindrical cylinder 19 Paper feed unit 20 Conveyor 21 Swing gripper 22 Blanket cylinder 23 Impression cylinder 24 Chain conveyor 25 Sheet guide 26 Arm (rotary body) 27 Axis 28 Threading R Axis P Action point

Claims (4)

[Claims] In a multicolor printing sheet-fed printing press, an air duct is used as a guide for paper provided near an outer periphery of an intermediate cylinder or a discharge shaft, and a plurality of air discharge nozzles are provided on a surface of the air duct. A sheet guide for a sheet-fed printing press, wherein the discharge nozzles face each other at the center of the machine and open toward both width ends. 2. The air discharge nozzle according to claim 1, wherein the air discharge nozzles face each other at the center of the machine and open toward both width ends. 2. The sheet guide for a sheet-fed printing press according to claim 1, wherein the sheet guide is opened in an intermediate direction of the sheet guide. 3. A duct having an air intake port at both ends of the air duct, and the duct is connected to an air suction side of an air supply means for supplying air to the air duct. A sheet guide for a sheet-fed printing press according to claim 1. 4. The sheet for a sheet-fed printing press according to claim 1, wherein the air discharge nozzle provided on the surface of the air duct is formed integrally with or separate from the air duct. guide.