JP2001294341A - Sheet guide device for paper sheet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet guide device for a paper sheet printer capable of preventing the generation of the turbulent flow of air passing through a sheet guide gap in the outer circumference of a printing drum, suppressing the fluttering of a sheet, and smoothly feeding even a thin sheet. SOLUTION: This sheet guide device has an intermediate drum in which a circular arc-shaped sheet guide surface is formed on the lower circumferential surface of a skeleton drum through a guide gap, a printing drum such as a paper delivery drum, and plural air ports in an air supply chamber installed in the back portion of the sheet guide surface, and the sheet is sucked on the sheet guide surface, slightly floated by the flow velocity difference in the upper and lower surfaces of the sheet carried by the rotation of the printing drum, and carried. At least a pair of air suction chambers is installed close to the air supply chamber on the exit outside positioned on the shaft end side of the skeleton drum on the sheet guide surface, the exit end of the sheet guide surface is extended to function as an air suction guide fin. The air amount sucked with the air suction chambers is increased than the air amount blown off from the air supply chamber to produce negative pressure in the vicinity of the exit end of the sheet guide surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-fed printing press for stabilizing the conveyance of a printing sheet, and more particularly, to a printing press, such as an intermediate cylinder or a paper discharge cylinder, which has a lower circumferential surface through a guide gap. The present invention relates to a sheet guide device for a sheet-fed printing press having an arcuate sheet guide surface.

[0002]

2. Description of the Related Art Conventionally, there has been known a multicolor printing sheet-fed printing press in which a plurality of sets of printing devices having different ink colors are juxtaposed in a tandem manner. As shown in FIG. Feeder unit (A) equipped with a paper device 39, cyan,
Multiple sets of magenta, yellow, and black printing devices (1
32a), (132b), (132c), (132d)
Are composed of a printing unit section (B) arranged in tandem, a delivery section (C) as a paper discharge section 04, and the like.

In the multi-color printing sheet-fed printing press having such a configuration, the sheets 11 stacked on the table 141 of the sheet feeding section 39 are separated one by one using a soccer section provided with a mouthpiece and conveyed. After being sent out via the first printing device 120, the swinging gripper 121a transfers the printing material to the first intermediate cylinder 121b of the first printing device 132a, and is further fed between the blanket cylinder 22a and the impression cylinder 23a to print the first color. Is applied.

[0004] The sheet on which the printing of the first color has been completed is carried out from between the blanket cylinder 22a and the impression cylinder 23a and delivered to the intermediate cylinder 27a of the second printing device 132b. To the blanket cylinder 22b and the impression cylinder 23
Perform at b.

[0005] Printing is sequentially performed for each color, and the sheet 11 sent out between the blanket cylinder 22d and the impression cylinder 23d for printing the final stage is discharged from the discharge cylinder 3 of the delivery section C.
5, the sheet 11 after printing is transferred from the paper discharge cylinder 35 to the chain conveyor 124, transported to the paper discharge unit 04, and stacked on the table 40 of the paper discharge unit 04.

In general, a printing sheet 11 to be printed in a sheet-fed printing press uses thin paper of about 0.04 m / m to thick paper of about 0.8 m / m. In some cases, a highly rigid sheet made of a synthetic resin is used. When the sheet is transported from the printing device 132a for each color to the next printing device 132b, thin paper generally has low rigidity and flutters at the rear end of the sheet. In the case of a high sheet, the centrifugal force caused by the rotational transfer and the reaction force (restoring force) against the bending of the sheet itself cause the rear end of the sheet to separate from the impression cylinder 23 and generate paper splatter that collides with the lower sheet guide device 1 '. Comes out.

[0007] The fluttering or splashing of paper causes stains on the printing surface, breaks and scratches on the sheet, and is a major factor in lowering print quality. For this reason, there are two typical types of the intermediate cylinder 27, a skeleton cylinder and a cylindrical cylinder, and the most suitable type is adopted depending on the rigidity of a frequently used sheet.

FIG. 6A shows a skeleton body type intermediate cylinder 27 mainly applied to a cardboard sheet.
The skeleton cylinder 27 of this type is disposed at both left and right width ends of the printing apparatus 132, and is constituted by a pair of rotating bodies (arms) 271 that rotate about an axis 270.
A plurality of sets of holding claws 29 are arranged in parallel on a shaft 272 (see FIG. 7A) extending from the tip of the arm 271 to the corresponding tip of the arm 271 on the opposite side of the shaft. The skeleton body 2
7 is characterized in that the contact area with the impression cylinder 23 engaged via the sheet 100 is minimized. The sheet 100 to be rotated and transferred is bent and deformed from a point (P) close to the gripper 29. Can be. In other words, the point (P) approaching becomes the point of action, and by increasing the distance from this point to the rear end of the sheet 100, the function of reducing the reaction force for returning the sheet 100 is improved.

As a result, a paper spring whose rear end impacts against the sheet guide device 1 'provided below the skeleton type intermediate cylinder 27 and extended in a concave arc shape along the virtual rotation circumferential line. Although it can be softened, it is possible to reduce scratches and bending deformation, but conversely, in the skeleton cylinder 27 of this type, the rear end free area of the sheet 100 to be transported is increased, so that in the case of thin paper, This would cause large sheet flapping.

On the other hand, an example shown in FIG. 6B is a cylindrical intermediate cylinder 27 'mainly applied to thin paper sheets.
It is. The cylindrical body 27 'of this type is a roll which rotates about an axis 270, and has a plurality of sets of holding claws 29 arranged at two corresponding positions in the circumferential direction.

The cylindrical cylinder 27 'is characterized in that the contact area with the impression cylinder 23 engaged via the sheet 100 is increased.
Is guided along the outer peripheral surface of the cylindrical body 27 ', so that the function of reducing the flapping at the rear end of the sheet 100 is enhanced, and this function reduces wrinkles and paper flapping generated at the rear end of the sheet. Although it is possible to reduce the problems such as doubling and scratching caused by this, on the other hand, in the case of the cylindrical intermediate cylinder 27 ′ of this type, when transferring thick paper, the free area of the sheet is reduced, so that stronger paper is used. That would cause spatter.

Therefore, in such sheet-fed printing presses, in order to solve the above-mentioned problems, especially in recent years, the printing quality has been improved, and the skeleton type intermediate cylinder tends to be used also for the thin paper. In order to suppress the occurrence of fluttering of sheets of thin paper, the sheet guide device 1 including an intermediate cylinder 27 and a sheet guide surface 1d provided along the lower periphery of a discharge cylinder 35 (hereinafter collectively referred to as an intermediate cylinder). ′, Air which is pressurized to a predetermined pressure and flows from a plurality of air outlets along the surface of the sheet guide surface 1d into the guide clearance formed between the intermediate body 27 and the sheet guide surface 1d. There has been proposed a sheet guide device in which the sheet 11 is ejected to the lower surface side of the passing sheet 11 and the sheet 11 is caused to float by the Bernoulli effect by the ejected air.

As one of such sheet guide devices, there is an invention disclosed in Japanese Patent Application Laid-Open No. Hei 10-109404. This technique will be described with reference to FIG. 7. The sheet guide device 1 'installed along the outer periphery of the skeleton-type intermediate cylinder 27 provided with the claws 29 or the outer periphery of the paper discharge cylinder 35 is constituted by an air duct 06. A plurality of air outlets 4a, 4a, 4b are provided on the surface of the air outlet duct 2 'located at a position corresponding to the sheet width of the air duct 06.
b, and the air outlets 4a, 4b are scattered and arranged so as to face each other at the center of the intermediate cylinder 27 and open toward both ends of the intermediate cylinder 27, An air stream is discharged from the air outlets 4a and 4b in the opening direction to regulate the sheet at a predetermined position, thereby stabilizing the running of the sheet.

That is, according to the prior art, on the lower surface side of the sheet 11 gripped by the claws 29 of the skeleton-type intermediate cylinder 27, a sheet guide surface 1d having a blowing duct 2 'on the lower surface and the intermediate cylinder 27 are provided. Along the guide gap between the air outlets 4a and 4b in the sheet width direction along the sheet guide surface, more specifically, as shown in FIG. Since the air is jetted toward the shaft both ends of the intermediate cylinder 27 with their backs facing each other,
After the sheet 11 conveyed along the peripheral surface of the intermediate cylinder 27 is transported while being suctioned and slightly floated to the sheet guide surface 1d side by the Bernoulli effect due to the difference in the flow velocity of the air flow between the upper and lower surfaces of the sheet, It is delivered to the impression cylinder 23 at the next stage.

In this apparatus, a suction duct 3 'having an opening at the exit end of the guide surface 1d is provided on both sides of the body shaft of the air blowing duct 2' having the air blowing ports 4a and 4b, and the suction duct 3 'and the inside thereof are provided. Are connected to each other through a fan 51 between the outlet ducts 2 ′.

As a result, the air blown out in the sheet width direction along the sheet guide surface 1d has the opening of the suction duct 3 'at the guide surface outlet end. And is blown out again from the blow-out duct 2 'to the air blow-out ports 4a and 4b.

[0017]

However, the prior art has the following problems. That is,
In the sheet guide device 1 ', the suction duct 3'
And the blow-out duct 2 ′ communicate with each other, so that the blow-out amount and the suction amount by the fan 51 are the same, but with the same suction amount, it is possible to suck all the air amount flowing along the sheet guide surface 1 d. In particular, since the sheet guide device 1 ′ is installed in two pairs of frames 011 that support cylinders and the like of a sheet-fed machine, the suction duct 3 ′ sends excess air into the machine. Of the air blown out from the plurality of air outlets 4, the remaining blown-out air which has not been sucked is subjected to the action of adsorbing the print sheet 11 to the sheet guide side, and then collides with the frame 011 to be generated in the machine. Unnecessary air turbulence is caused, and especially in the case of printing paper using thin paper, fluttering or the like is likely to occur at the width end.

For this reason, in the prior art, as shown in FIG. 8, the air suction duct 3 'and the air blowing duct 2' are
2, the air is blown out by using a pump 13 'instead of a fan.

However, even in such a configuration, the amount of air blown out and the amount of suction by the pump are the same as in FIG. 7, and in the case of the prior art, in particular, the flow velocity of air blown out from the nozzle on the guide surface is reduced. High speed (about 20-30m / s)
Because the inertial force of air is dominant, a turbulent boundary layer grows below the blowing nozzle and the “thickness” of the air flow itself
And the distance from the sheet guide surface increases.

For this reason, in the prior art, the efficiency of the air flow ejected from both ends of the sheet guide to be collected in the outlet chambers provided on both sides is low, and the air flow collides with the frame to cause printing. When turbulence of air occurs in the frame of the machine, the turbulence also causes turbulence in the air flow in the guide gap on the upstream side, and in the case where the sheet is thin paper that is liable to flutter or flutter at the end, In addition, the fluttering and paper flapping at the end of the sheet are increased, and it is substantially difficult to transfer the sheet using the skeleton intermediate cylinder.

In view of the above-mentioned problems of the prior art, the present invention passes a sheet through a guide gap formed between the outer periphery of a printing cylinder and a sheet guide, and blows air from the air outlet of the sheet guide into the guide gap. In the sheet-fed printing press configured to cause the sheet to flutter by avoiding the occurrence of turbulence due to collision of an air flow ejected from both ends of the sheet guide through the guide gap with a frame or the like, It is an object of the present invention to provide a sheet guide device of a sheet-fed printing press that can suppress thin paper and smoothly transfer thin paper sheets even with a skeleton type cylinder suitable for thick paper.

[0022]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to an intermediate cylinder having an arc-shaped sheet guide surface formed on a lower peripheral surface thereof with a guide gap therebetween, and a paper discharge device. A printing cylinder such as a cylinder, an air supply chamber provided at the sheet guide surface rear part, and are arranged so as to be opened from the supply chamber on the sheet guide surface,
A plurality of air outlets for turning the back with respect to the center of the printing cylinder and ejecting air toward both ends of the intermediate cylinder in a sheet width direction along a sheet guide surface; The sheet guide device in a sheet-fed printing press configured to be able to convey while suctioning and slightly floating on the sheet guide surface side by the flow velocity difference of the air flow on the upper and lower surfaces of the sheet transferred according to the rotation of At least a pair of left and right air suction chambers are provided adjacent to the air supply chamber on the outer side of the outlet end located on the body shaft end side of the sheet guide surface,
The outlet end of the sheet guide surface is extended, and the extended portion is caused to enter the air suction chamber to function as an air suction guide fin. A sheet-fed printing machine characterized in that the amount of suction air sucked by each air chamber is made larger than the amount of air blown out to the suction chamber so that the pressure near the outlet end of the sheet guide surface becomes negative. Is proposed.

The specific configuration of the guide fin is as described in claim 2 or 3, wherein the cross-sectional shape of the guide fin is lower than the surface of the sheet guide by a predetermined inclination angle (α) of 20 to 40 ° range, preferably inclination angle α = 3
It may be constituted by a straight fin inclined at about 0 °, or may be constituted by a curved fin having a cross-sectional shape curved toward the inside of the air suction chamber.

Further, the specific structure of the relationship between the amount of blown air and the amount of sucked air is as described in claim 4 or 5, wherein the air discharge pump connected to the air suction chamber and the air supply chamber are provided. Air supply pumps connected to the air supply pump, the discharge capacity of the air discharge pump may be configured to be larger than the supply capacity of the air supply pump, and the air suction chamber and the air supply chamber may be connected by an air circulation pump. And a relief valve may be provided between the discharge side of the air circulation pump and the air supply chamber to allow a part of the air in the air circulation path to escape.

According to this invention, the outlet end of the sheet guide on both shaft end sides of the printing cylinder is configured to have a negative pressure, and the outlet end is extended, and the extended portion enters the air suction chamber. As a result, even if the airflow along the sheet guide surface is accelerated, all the airflow guided to the exit end of the sheet guide is guided as it is along the guide fins. And sucked into the air suction chamber.

Therefore, the air flow flowing along the guide gap does not overflow and flow to the frame side to cause fluttering of the thin paper transport printing paper. In other words, the air flow in the entire guide gap does not occur. The turbulence of the air flow can be minimized, and the thin paper can be smoothly conveyed even when a skeleton cylinder is used as in the sixth aspect of the invention.

In addition, the air is efficiently guided to the suction chamber, and the boundary layer of the sheet guide surface near the outlet end becomes thinner due to the negative pressure effect at the outlet end of the sheet guide. The inhibition of the growth facilitates the suction of the thin paper sheet toward the front side of the sheet guide when printing the thin paper sheet, so that the thin paper sheet can be prevented from fluttering and paper flapping.

Therefore, according to the invention, the negative pressure effect and the guide fins prevent the turbulent flow from growing near both ends of the exit of the sheet guide surface, and a flow with little turbulence is formed in the entire guide gap. At the same time, the turbulent boundary layer between the air jet and the lower surface of the sheet is thinned, and the fluttering and paper flapping of the sheet are suppressed, and the sheet is
The inside of the guide gap can be smoothly transferred.

Thus, with a very simple and low-cost device of increasing the amount of suction air and the guide fin,
By using the skeleton-type cylinder, the thin paper sheet can be smoothly transferred without causing fluttering or paper flapping.

Since the guide fins have the above-described structure, they flow smoothly along the surface of the fins, so that separation in the flow path is less likely to occur, and turbulent growth in the guide gap is suppressed. Becomes stable.

Further, the negative pressure effect at the outlet end suppresses the growth of the turbulent boundary layer on the sheet guide, the thickness of the boundary layer becomes thin, the flow becomes stable, and the Bernoulli effect in the guide gap increases. Although the effect of smoother sheet transfer can be achieved by connecting independent pumps having different capacities, air is circulated along the air circulation path of the air suction chamber and the air supply chamber. This is also achieved by a relief valve that allows a part of the air on the discharge side of the air circulation pump to escape,
Since only one air circulation pump needs to be provided, the apparatus cost is reduced. Further, by adjusting the opening of the relief valve, the flow rate and pressure of the air flowing through the air circulation pipe can be controlled, and the Bernoulli effect in the guide gap can be easily adjusted.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to an embodiment shown in the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. It's just

FIG. 1 is a cross-sectional view of a main part of a sheet guide portion and its vicinity in a first embodiment of a sheet guide device of a sheet-fed printing press according to an embodiment of the present invention (a view taken along the line AA in FIG. 5). FIG. 2 is a cross-sectional view of a main part near an end of a sheet guide showing a second embodiment. FIG. 3 is a perspective view of a main part showing a third embodiment.
4 is a system diagram of the air in FIG.

In the present embodiment, the intermediate cylinder 27 and the paper discharge cylinder 35
The present invention relates to a sheet guide device 1 including a sheet guide surface 1d provided along the outer periphery of a lower portion of the intermediate cylinder (hereinafter, generically referred to as an intermediate cylinder). In this embodiment, a skeleton cylinder is used for the intermediate cylinder. Reference numeral 29 denotes claws for holding a plurality of sheets 1 provided in the longitudinal direction of the skeleton intermediate body 27. 01
Reference numeral 1 denotes a frame that rotatably supports both ends of the skeleton intermediate body 27.

As described above, the sheet guide device 1 has an upper surface formed with an arc-shaped sheet guide surface 1d with the lower outer periphery of the intermediate cylinder 27 and the guide gap 15 for air flow. On the back side of the sheet guide surface 1d, a plurality of air supply chambers 2 are formed in substantially the entire area of the sheet guide surface 1d or distributed to the left and right in the width direction with a central partition wall interposed therebetween. Numeral 4 is an air outlet formed by drilling a plurality of holes in the sheet guide 1d. As shown in FIG. 7 (B), the guide gap 15 and the air supply chamber 2 communicate with each other, and Are arranged scatteredly so as to open toward both ends of the intermediate cylinder 27, and discharge air in the opening direction from the air outlet 4 to place the sheet in a predetermined position. Regulations are made to stabilize the running of the seat.

That is, on the lower surface side of the sheet 11 gripped by the claws 29 of the skeleton type intermediate cylinder 27, along the guide gap 15 between the sheet guide surface 1d having the air supply chamber 2 on the lower surface and the intermediate cylinder 27. Since air is ejected from the left and right air outlets 4 in the direction along the lower surface of the sheet toward the width direction or the obliquely upstream side along the sheet guide surface 1d, the Bernoulli due to the difference in air flow velocity between the upper and lower surfaces of the sheet. As a result, the sheet 11 conveyed along the peripheral surface of the intermediate cylinder 27 is conveyed while being suctioned and slightly levitated toward the sheet guide surface 1d. The arrangement and the opening direction of the plurality of air outlets 4 are not limited to the embodiment shown in FIG.

Reference numeral 6 denotes an air supply pipe connected to the air supply chamber 2, and reference numeral 9 denotes an air supply pump provided in the air supply pipe 6.

The air supply chamber 2 is formed on the back side of the skeleton intermediate cylinder 27 over the entire width of the sheet guide surface 1d substantially corresponding to the axial length. Place each one. As shown in FIG. 3, the air suction chamber 3 is formed in an arc shape having the same length as the air supply chamber 2 along the sheet conveying direction.

The inlet opening (air suction passage 10) of the air suction chamber 3 is provided with an upper wall of the inlet opening (air suction passage 10) so as to efficiently catch the air blowing flow flowing through the sheet guide and the lower surface of the conveying sheet 11. 1c is set at the upper surface position of the guide gap 15 which is almost close to the peripheral surface of the intermediate cylinder 27,
The lower surface side of the inlet opening (air suction passage 10) is extended 1a with the outlet end 1d1 of the sheet guide surface 1d, and the extended portion 1a is caused to enter the air suction chamber 3 so that the sheet guide surface 1d (See FIG. 3) to function as air suction guide fins 1a.

The cross section of the guide fin 1a has an inclination angle α downward from the outlet end 1d1 of the sheet guide surface 1d.
And is inclined into a straight fin shape and enters the air suction chamber 3. The inclination angle α is preferably 20 to 40 °, preferably around 30 °.

An air discharge pipe 5 is provided in the air suction chamber 3.
And an air supply pump 9 connected to the air supply chamber 2 through the air supply pump 9 to supply air evenly into the air supply chamber 2 by a branched air supply pipe 6. The discharge capacity of the discharge pump 7 is larger than the supply capacity of the air supply pump 9.

Next, the operation of the sheet guide device 1 of the sheet-fed printing press having the above configuration will be described. The thin paper sheet 11 sent out from the front-side impression cylinder 23 is gripped by the claws 29 of the skeleton intermediate cylinder 27 to guide the guide gap 15 formed between the skeleton intermediate cylinder 27 and the sheet guide 1. pass.

On the other hand, in the air supply chamber 2, air pressurized to a predetermined pressure by the air supply pump 9 is supplied to the entire area of the chamber 2 via the air supply pipe 6. The equalized air flows along the guide gap 15 between the sheet guide surface 1d and the intermediate cylinder 27,
As shown in FIG. 7B, the back of the intermediate cylinder 27 is turned from the air outlet 4 to the center of the intermediate cylinder 27,
Since air is ejected toward both ends of the shaft of the sheet 7, the sheet 11 conveyed along the peripheral surface of the intermediate cylinder 27 by the Bernoulli effect due to the flow velocity difference of the air flow between the upper and lower surfaces of the sheet, The skeleton intermediate cylinder 27 passes through the guide gap 15 due to the rotational transfer of the skeleton intermediate cylinder 27 while being suctioned and slightly floated to the surface 1d side.

The air passing through the guide gap 15 passes through the air suction passage 10 formed between the guide fin 1a and the upper wall 1c of the air suction chamber 3 as shown by the arrow in FIG. It flows into the air suction chamber 3.

At this time, since the capacity of the air discharge pump 7 is configured to be larger than the capacity of the air supply pump 9, the air suction chamber 3
The suction force of the air suction path 10 passing through the guide gap 15 through 0 increases, and the Venturi effect in the guide gap 15 increases, so that the sheet can be transported more smoothly than the sheet particularly on the inlet side of the air suction chamber 3. In particular, increasing the amount of air suction than the amount of air blown out requires the suction chamber 3
The outlet end of the sheet guide 1d on the inlet side is in a negative pressure state, so that the thickness of the turbulent boundary layer formed on the sheet guide surface 1a is reduced, and the growth of turbulent flow near the outlet end is suppressed. As a result, a stable blowout flow is obtained in a laminar flow state, and the fluttering and flapping of the conveyed sheet 11 are minimized.

The outlet end 1d1 of the sheet guide surface 1a is extended so as to enter the suction chamber 3 side and functions as the guide fin 1a.
The air flowing out of the fin is guided by the guide fins 1 a and guided to the air suction passage 10. Therefore, the outlet end 1d1
Along with the negative pressure effect, the blowing air flows toward the suction chamber 3 by the guide fins 1a, and the air after passing the width end of the sheet 11 is reliably collected in the suction chamber side, and the air rebounds in the frame 011. In addition, the turbulence on the sheet width end side is eliminated, and the air layer on the sheet guide 1 is guided to the air suction chamber 3, so that the problem caused by the turbulent air flow can be eliminated.

According to the experiments conducted by the present inventors, when the inclination angle α of the guide fin 1a greatly exceeds 30 °, the air flow guided to the air chamber is separated from the surface of the guide fin 1a. A vortex is generated in this portion, and turbulence occurs in the air flow inside the guide gap 15. When the inclination angle α becomes 30 ° or less and the inclination becomes small, the air flowing through the air outflow passage 10 along the guide fin 1a collides with the wall surface of the air suction chamber 3 to generate a return turbulent flow. And the like. Therefore, the inclination angle α20 to
The angle is preferably 40 °, preferably around 30 °.

The effect of the negative pressure generated by the outlet end 1d1 of the guide gap 15 prevents the growth of turbulence, and the boundary layer on the surface of the sheet 11 by the air jet in the guide gap 15 is thinned. At the time of printing the sheet, the suction of the sheet 11 toward the front surface 1d of the sheet guide 1 is facilitated, and the fluttering of the sheet 11 and the flapping of the sheet 11 are suppressed.

In the second embodiment shown in FIG.
The guide fin is a curved fin 1a having a cross section bent into the air suction chamber 3 having an arc shape or the like.
And the upper side wall 1c of the guide fin 1a of the air suction chamber 3 constituting the inlet opening (air suction path 10) of the air suction chamber 3 has a curved surface corresponding to the guide fin 1a. Has formed.

According to this embodiment, the air flow passing through the guide gap 15 flows smoothly along the surface of the guide fin 1a formed in a curved surface together with the negative pressure effect of the sheet guide surface outlet end 1d1, so that the flow Separation hardly occurs in the road, and laminar flow in the guide gap 15 is promoted.

In the third embodiment shown in FIGS. 3 and 4, an air circulation path 8 is provided which is connected from the air suction chamber 3 to the air supply chamber 2 via an air discharge pipe 5 and an air supply pipe 6. One air circulation pump 1
3, a relief valve 14 is provided between the discharge side of the air circulation pump 13 and the air supply chamber 2 to allow a part of the pump discharge air to escape.

Now, from the basic data of the turbulent flow study of the fluid dynamics, if the disturbance element to the flow of the pump or the like that drives the inside of the flow path is the same, if the flow path system is a circulating closed loop, In the open loop, the turbulence component in the flow can be suppressed to a lower level by taking a circulating flow path. Also, less energy is required to drive the channel system.

That is, according to this embodiment, the air continuously circulating in the air circulation path 8 is
Since the air flows, the air flow is smooth and turbulence is less likely to occur. In addition, since only one air circulation pump 13 needs to be provided, the cost of the apparatus is reduced.

In this embodiment, the air circulation pump 1
Since the relief valve 14 is provided on the outlet side of the air supply chamber 3, the air discharge from the air suction chamber 3 can be made larger than the supply amount supplied to the air supply chamber 2 through the air supply pipe 6. The smooth suction of the air suction chamber 3 and the negative pressure effect at the sheet guide outlet end can be achieved smoothly. In this case, by adjusting the opening of the relief valve 14,
The air blowing amount and the suction amount can be easily adjusted, the Renault effect can be easily adjusted, appropriate negative pressure adjustment at both ends of the sheet guide 1 and the guide fin 1a can be performed.
As a result, the growth of the turbulent flow is prevented and a smooth laminar flow is formed in the entire inside of the guide gap 15, and the boundary layer between the guide surface and the surface of the sheet 11 due to the air jet becomes thin, so that the sheet 11 flutters. In this way, the thin paper sheet can be smoothly transferred without flapping or paper flutter even when the skeleton intermediate cylinder 27 is used.

In the above embodiment, the sheet guide device is provided on the intermediate cylinder 27.
1b, the present invention can also be applied to a sheet guide device provided on a paper discharge cylinder and a printing cylinder.

[0056]

As described above, according to the present invention, a stable flow with little turbulence is formed at both ends of the sheet guide, and the turbulent boundary layer on the sheet surface due to the air jet becomes thin, and the sheet flutters. This prevents the sheet from being loosened and smoothly transports the sheet in the guide gap, and also prevents the air from colliding with the frame or the like and causing turbulence inside the machine.

This makes it possible to smoothly transfer the thin paper sheet using the skeleton type intermediate cylinder without flapping or paper skew, and to use the skeleton type intermediate cylinder for sheets of all thicknesses. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view (a view taken along the line AA in FIG. 5) of a sheet guide portion and a main portion in the vicinity thereof in a first example of a sheet guide device of a sheet-fed printing press according to an embodiment of the present invention. .

FIG. 2 is a cross-sectional view of a main part near the end of a sheet guide showing a second embodiment.

FIG. 3 is a perspective view of a main part showing a third embodiment.

FIG. 4 is a system diagram of the air in FIG. 3;

FIG. 5 is an overall configuration diagram of a sheet-fed printing press to which the present invention is applied.

6A and 6B show the types of the intermediate cylinder, wherein FIG. 6A shows a skeleton cylinder and FIG. 6B shows a cylindrical cylinder.

7A and 7B are front cross-sectional views illustrating a configuration of a main part of a conventional technique, in which FIG. 7A is a front cross-sectional view illustrating a configuration around a skeleton type intermediate cylinder and a sheet guide device installed along an outer periphery thereof, and FIG. 1 shows the configuration of the surface.

FIG. 8 is a front sectional view showing another configuration of the main part of the prior art, showing the configuration around a skeleton type intermediate cylinder and a sheet guide device installed along the outer periphery thereof.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sheet guide 1 a, 1 b guide fin 1 d surface of sheet guide 2 air inlet chamber 3 air outlet chamber 4 air outlet 5 air discharge pipe 6 air supply pipe 7 air discharge pump 9 air supply pump 10 air outflow path 11 sheet 13 air circulation Pump 14 Relief valve 15 Guide gap 22a Blanket cylinder 23a Impression cylinder 27 Intermediate cylinder (skeleton intermediate cylinder)

Claims (6)

[Claims] 1. A printing cylinder such as an intermediate cylinder or a paper discharge cylinder having an arcuate sheet guide surface formed on a lower peripheral surface thereof with a guide gap interposed therebetween, and an air supply chamber provided at a rear portion of the sheet guide surface. The supply chamber is scattered and arranged so as to open above the sheet guide surface, the backs are turned each other around the center of the printing cylinder, and the sheet width direction along the sheet guide surface toward both ends of the intermediate cylinder. A plurality of air outlets for ejecting air in the direction, and the sheet is sucked and slightly moved toward the sheet guide surface due to a difference in air flow velocity between the upper and lower surfaces of the sheet transferred according to the rotation of the printing cylinder. In a sheet guide device for a sheet-fed printing press configured to be capable of being conveyed while being floated, the sheet guide device may include a sheet guide surface adjacent to the air supply chamber outside an outlet end located on a cylinder shaft end side of the sheet guide surface. At least a pair of left and right air suction chambers are provided, and the outlet end of the sheet guide surface is extended, and the extended portion is caused to enter the air suction chamber to function as an air suction guide fin. By making the amount of suction air that each air chamber is sucked larger than the amount of air blown out to each corresponding air suction chamber at the center of the printing cylinder,
A sheet guide device for a sheet-fed printing press, wherein a pressure near the exit end of the sheet guide surface is negative. 2. The guide fin is formed of a straight fin having a cross-sectional shape lower than a surface of the sheet guide and a predetermined inclination angle (α) inclined in a range of 20 to 40 °. The sheet guide device for a sheet-fed printing press according to claim 1, wherein: 3. An air discharge pump connected to the air suction chamber and an air supply pump connected to the air supply chamber are provided, and the discharge capacity of the air discharge pump is set to be smaller than the supply capacity of the air supply pump. The sheet guide device for a sheet-fed printing press according to claim 1, wherein the sheet guide device is also configured to be large. 4. An air discharge pump connected to the air suction chamber and an air supply pump connected to the air supply chamber are provided, and the discharge capacity of the air discharge pump is made larger than the supply capacity of the air supply pump. The sheet guide device for a sheet-fed printing press according to claim 1, wherein the sheet guide device is also configured to be large. 5. An air circulation path for circulating the air suction chamber and the air supply chamber through an air circulation pump, and an air circulation path between a discharge side of the air circulation pump and the air supply chamber. 2. A relief valve for escaping a part of the air in the interior.
A sheet guide device for a sheet-fed printing press as described above. 6. A printing cylinder such as an intermediate cylinder or a paper discharge cylinder having an arcuate sheet guide surface formed on a lower peripheral surface of a skeleton cylinder via a guide gap, and an air supply provided on a rear portion of the sheet guide surface. And the chambers are scattered and arranged so as to be opened on the sheet guide surface from the supply chamber, and the back faces each other with the center of the printing cylinder as a boundary, and along the sheet guide surface toward both ends of the intermediate cylinder. A plurality of air outlets for ejecting air in the sheet width direction are provided, and the sheet is sucked toward the sheet guide surface due to a difference in air flow velocity between the upper and lower surfaces of the sheet transferred according to the rotation of the printing cylinder. And a sheet guide device in a sheet-fed printing press configured to be capable of being conveyed while being slightly floated, wherein the sheet guide surface is provided at an outer side of an exit end located on an end side of a skeleton cylinder shaft. At least a pair of left and right air suction chambers are provided adjacent to the air supply chamber, an outlet end of the sheet guide surface is extended, and the extended portion is inserted into the air suction chamber to guide air suction guide fins. And the amount of air suctioned by each air chamber is made larger than the amount of air blown out to the corresponding air suction chamber at the center of the printing cylinder, and the vicinity of the exit end of the sheet guide surface A sheet guide device for a sheet-fed printing press, wherein the sheet guide device has a negative pressure.