JPH11138742A - Sheet-feed printer for double-side printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet-feed printer for double-side printing which is capable of eliminating a change in the color tone of a printed face and thereby improving print quality by controlling the temperature of an impression cylinder. SOLUTION: This sheet-feed printer for double-side printing comprises an impression cylinder 3 through which water 14 for temperature regulation flows internally, a rotary joint 7 which is mounted on the impression cylinder 3 and circulates the water 14 to the inside/outside of the impression cylinder 3, a water circulation device 6 which is connected to the rotary joint 7 and circulates the water 14, a water temperature regulator 5 which is connected to the rotary joint 7 and regulates the temperature of the water 14, a target temperature setting device 27 which sets a target temperature for the water 14 to be controlled and a temperature regulation control device 11 which controls the operation of each of the devices including the water temperature regulator 5.

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 double-sided printing, and more particularly to a sheet-fed printing press for double-sided printing configured to print on both sides of a sheet.

[0002]

2. Description of the Related Art Conventional sheet-fed printing presses for duplex printing include:
For example, those shown in FIGS. 4 to 10 have been proposed. That is, FIG. 4 is an explanatory view showing a partial configuration of a general sheet-fed printing press for double-sided printing provided with a reversing mechanism, and FIG. 5 is an explanatory view showing a state of a double-sided printing sheet traveling between a blanket cylinder and an impression cylinder. Figure,
6 is an explanatory diagram showing a change in temperature of each part with the passage of the printing time, FIG. 7 is an explanatory diagram showing a change in the ink density of the printed matter with the passage of the printing time, and FIGS. FIG.

As shown in FIG. 4, a general sheet-fed printing press for double-sided printing includes a paper feeding unit (not shown), a printing unit P, a paper discharging unit (not shown), and the like. In the printing device P, a plurality of printing devices 25 having different colors of the ink 16 are usually arranged side by side along the traveling direction of the printing sheet 12 in the printing device P. By sequentially passing the supplied sheet 12 to each printing device 25, multicolor printing can be performed on the surface of the sheet 12. The sheet-fed printing press may be configured as a single-sided printing sheet-fed printing machine that prints on only one side of the sheet 12 to be passed, or a double-sided printing sheet-fed printing machine that prints on both front and back sides of the sheet 12. There is.

[0004] Such a set of printing devices 25 mainly includes an ink reservoir 19 formed by an ink source roller 17 and an ink blade 18, a call roller 20, a group of various ink rollers 21 arranged in parallel, and a printing plate 22. It is composed of elements such as the plate cylinder 23, the blanket cylinder 24, the impression cylinder 3 and the intermediate cylinder 31 which are mounted.

In the sheet-fed printing press having the above-described configuration, the ink 16 supplied to the ink reservoir 19 passes through a gap between the ink source roller 17 and the ink blade 18 and is supplied to the ink source roller 17.
Is applied as an ink film to the outer peripheral surface of the
7 is rotated and transferred by an ink roller 21 via a call roller 20 which comes into contact with and separates from the ink source roller 17.
Handed over to the side. Thereafter, the ink 16 is appropriately kneaded in the process of sequentially rotating and transferring the group of ink rollers 21 arranged side by side, and is supplied to the printing plate 22 wound around the plate cylinder 23 and further to the blanket cylinder 24, and is supplied to the blanket cylinder 24. A predetermined printing is performed on the sheet 12 traveling between the impression cylinder 3 and the impression cylinder 3.

Here, the sheet-fed printing press illustrated in FIG. 4 is a sheet-fed printing press for duplex printing of a type having a reversing mechanism (detailed description is omitted) 26, and the surface of the sheet 12 is subjected to an upstream process. After performing a predetermined printing on the sheet 12, the sheet 12 is reversed (turned over) through the reversing mechanism 26, and then a predetermined printing is performed on the back side of the sheet 12 in a downstream process. It is configured so that printing is performed on both sides. In addition, as a sheet-fed printing machine for double-sided printing,
In addition to the example illustrated in FIG. 4, a two-sided printing machine or the like, in which the impression cylinders 3 are juxtaposed, and printing is performed on both sides of the sheet 12 for each color,
There are various types of printing presses (not shown).

In the sheet-fed printing press, printing is performed on the opposite side of the sheet 12 on which printing has already been completed. For this reason, drying of the ink 16 printed in the immediately preceding process is not timely, and the viscosity of the undried ink 16 tends to cause a phenomenon that the sheet 12 sticks and becomes difficult to separate from the impression cylinder 3. As means for preventing this tendency, the outer peripheral surface 3a of the impression cylinder 3 which is brought into contact with the surface on which printing has been completed is usually formed in a matte surface having fine irregularities. Accordingly, as shown in FIG. 5, the ink 16 on the printing surface that comes into contact with the outer peripheral surface 3a of the impression cylinder 3 having a matt surface is used as shown in FIG.
4 to the sheet 12, and the ink 16 on the printed sheet 12 on the back side contacts the outer peripheral surface 3a of the impression cylinder 3, so that the ink 16 is also transferred to the outer peripheral surface 3a of the impression cylinder 3. Become. Note that the arrow a in FIG. 5 indicates the transfer direction of the ink 16.

In general, the temperature of each part during printing, for example, the temperature T _{1 of the} ink 16 that transfers the ink rollers 21, the temperature T ₂ of the surface of the printing plate 22 and the blanket cylinder 24, and the outer peripheral surface 3 a of the impression cylinder 3 temperature T ₃ of, as shown in FIG. 6, increases with the passage of printing time. In single-sided printing machine S, as shown in FIG. 7, the change in density becomes the temperature increase substantially in phase temperature T ₁ of the 16 parts of the ink, the reciprocating roller (ink distribution roller, for example, the ink roller 21) by the temperature control, such as, The color tone can be stabilized.

However, in the duplex printing machine W, when the temperature of the impression cylinder 3 is low, the transfer of the ink 16 to the back surface of the sheet 12 is not stable, so that the color tone becomes unstable and the print density fluctuates (falls). The trend comes out. That is, in double-sided printing, the printing quality of the preceding printing surface after the sheet 12 is reversed by the reversing mechanism 26 is the transfer (transfer) of the ink 16.
However, there is a problem that the color of the printed surface is liable to change because the color is not stable. The following can be considered as one of the causes. The relative temperature difference of the outer peripheral surface 3a of the impression cylinder 3 with respect to the temperature of the ink 16 on the lower surface of the sheet 12 makes the ink 1
The transition of No. 6 is as shown in FIGS. That is, when the temperature of the impression cylinder 3 is high, as shown in FIG. 8, the ink viscosity on the impression cylinder 3 side decreases, and the transfer of the ink 16 from the remaining ink 16 on the impression cylinder 3 to the sheet 12 side increases. And
The print density on the sheet 12 side increases.

When the temperature on the impression cylinder 3 side is low, FIG.
As shown in (2), the ink viscosity on the impression cylinder 3 side increases, the transfer of the ink 16 from the sheet 12 to the impression cylinder 3 side increases, and the print density on the sheet 12 side tends to decrease. FIG. 10 shows a case where the ink temperature on the lower surface of the sheet 12 and the temperature on the outer peripheral surface 3a of the impression cylinder 3 are equal, and the separation of the ink 16 to the opposite sides of the sheet 12 and the impression cylinder 3 is equal. Therefore, the print density does not change and a stable state is obtained.

[0011]

As described above, especially in a two-sided printing machine, after the sheet 12 is turned over, the temperature of the ink 16 on the preceding printing surface and the temperature of the outer peripheral surface 3a of the impression cylinder 3 which is in rolling contact with the printing surface. The amount of ink 16 transferred to the sheet 12 side or the impression cylinder 3 side, that is, the ink 16
Is fluctuated, so that the ink density of printing varies. However, in the conventional double-sided printing machine, measures for addressing the above-described problem are not considered, and a large factor that deteriorates print quality remains.

The present invention has been made in view of the above circumstances, and an object of the present invention is to control the temperature of an impression cylinder to eliminate a color tone change on a printing surface and to improve print quality. It is an object of the present invention to provide a sheet-fed printing press for double-sided printing.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention according to claim 1 has an impression cylinder through which a temperature adjusting liquid flows, and is provided on the impression cylinder. A rotary joint that circulates the liquid inside and outside the impression cylinder; a liquid circulation device that is connected to the rotary joint and circulates the liquid; and a liquid temperature controller that is connected to the rotary joint and adjusts the temperature of the liquid. When,
The apparatus includes a target temperature setting device for setting a target temperature of the liquid to be controlled, and a control device for controlling operation of each device including the liquid temperature controller.

According to a second aspect of the present invention, in the first aspect of the present invention, a sensor for measuring the surface temperature of the impression cylinder, the temperature measured by the sensor, and the target temperature setting device are related to the impression cylinder. And an arithmetic and control unit that obtains a difference from the target value set in step (1) and issues an operation command to the liquid temperature controller.

According to a third aspect of the present invention, there is provided a heating means provided in proximity to the outer peripheral surface of the impression cylinder, a sensor for detecting the temperature of the outer peripheral surface of the impression cylinder, A target temperature setting device that sets a target temperature to be adjusted and a control device that calculates a difference between the temperature detected by the sensor and the target temperature, issues an operation command, and controls heating by the heating unit. Have.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments. However, components common to the components shown in the conventional example are denoted by the same reference numerals, and description thereof will be simplified. Here, FIG. 1 is an explanatory view of a sheet-fed printing press for duplex printing according to the first embodiment of the present invention, and FIG.
It is sectional drawing which follows the -A line.

As shown in FIGS. 1 and 2, the sheet-fed printing press for duplex printing according to the first embodiment has a structure in which a liquid (water) 14 for temperature adjustment can flow through the inside of the impression cylinder 3. A rotary joint 7 for circulating water 14 inside and outside the impression cylinder 3 is provided at one axial end of the impression cylinder 3, and a liquid circulating device ( Water circulation device) 6 is connected,
A liquid temperature controller (water temperature controller) 5 for adjusting the temperature of the water 14 is connected, and a target temperature setting device 27 for setting a target temperature of the water 14 to be controlled is provided. A control device (temperature control device) 11 for controlling the operation of each device such as the controller 5 and the target temperature setting device 27 is provided. In connection with the impression cylinder 3, a sensor 10 for measuring the surface temperature of the impression cylinder 3, and a difference between the temperature measured by the sensor 10 and a target value set by the target temperature setting device 27 is obtained. An operation control device 28 for issuing an operation command to the temperature controller 5 is provided.

That is, as shown in FIGS. 1 and 2, the impression cylinder 3 installed in the sheet-fed printing press for double-sided printing according to the present embodiment includes:
Both ends of the frame 1 on the left and right sides through the bearing 2
a and 1b are each rotatably supported and formed as a hollow body having a hollow interior. In addition, a liquid supply pipe (water supply pipe) 4 inserted into the shaft center is disposed inside the impression cylinder 3 in order to quickly bring the entire outer peripheral surface to a uniform temperature. A water circulating device 6 including a water temperature controller 5 and a pump is provided outside the impression cylinder 3, and a supply part and a discharge part of the water 14 are independently provided to a shaft end of the impression cylinder 3. The rotary joint 7 and the water temperature controller 5 are connected to each other by pipes 8 and 9.

Further, a sensor 10 for detecting the surface temperature of the impression cylinder 3 is provided on the outer peripheral surface of the impression cylinder 3 in close proximity thereto, and a temperature control device is associated with the sensor 10. Eleven are equipped. In the temperature control device 11, the printing ink temperature data of the lower surface of the sheet 12 (the sheet surface in contact with the impression cylinder 3) obtained by experiments and running while rolling on the impression cylinder 3, or as shown in FIG. In order to actually measure the temperature of the ink 16 on the surface of the sheet 12 in contact with the impression cylinder 3, a signal of printing ink temperature data sent from an ink temperature detection sensor 13 disposed on the upstream side adjacent to the impression cylinder 3, 3 and a signal from the sensor 10 for detecting the surface temperature. Thus, the temperature control controller 11
Is configured such that the output of the water temperature controller 5 can be appropriately controlled by calculating the input data.

For this purpose, the temperature control controller 11 includes a target temperature setting device 27 and an arithmetic control device 28,
The surface temperature of the impression cylinder 3 is set to a predetermined temperature relative to the temperature of the ink 16 immediately before coming into contact with the impression cylinder 3 by the water circulation device 6, the water temperature controller 5, the sensor 10, the ink temperature detection sensor 13, and the like. It is configured to control so that In FIGS. 1 and 2, FL indicates a floor surface.

In the sheet-fed printing press for double-sided printing according to the present embodiment configured as described above, the calculated temperature data (temperature difference) is fed back to the water temperature controller 5 via the temperature controller 11. Then, the water temperature inside the water temperature controller 5 is controlled, and water 14 is fed into the impression cylinder 3 via the pipe 8 and the rotary joint 7 as shown by the arrow in FIG.

Next, the water 14 circulated inside the impression cylinder 3
As shown by the arrow in FIG. 1, the water is returned from the rotary joint 7 to the original water temperature controller 5 through the pipe 9. Less than,
Similarly, when the circulation of the water 14 is repeated, the temperature of the outer peripheral surface of the impression cylinder 3 can be accurately maintained based on the set value (temperature data).

As a method of controlling the temperature of the surface of the impression cylinder 3, a method of directly matching the temperature data from the ink temperature detection sensor 13 via the temperature control device 11, or a method substantially corresponding to the temperature data Various methods can be adopted, such as a method of inputting data along a control curve and performing simple control.

According to the sheet-fed printing press for duplex printing of the present embodiment, the following effects can be obtained. (1) Separation state of the ink 16 on the surface of the impression cylinder 3,
In other words, the amount of the ink 16 on the printing surface remaining on the sheet 12 side and
Since the amount of transfer to the impression cylinder 3 can be balanced (stabilized) at a predetermined ratio, there is no change in color tone. (2) Since print disturbances such as a change in ink density and double fog are eliminated, print quality can be improved.

FIG. 3 is an explanatory view of a sheet-fed printing press for duplex printing according to a second embodiment of the present invention. However, the same reference numerals are given to the same components as those in the conventional example and the first embodiment, and the description thereof will be omitted.

As shown in FIG. 3, the sheet-fed printing press for double-sided printing according to the second embodiment includes a heater (hot-wire type heater) 15 of heating means provided close to the outer peripheral surface of the impression cylinder 3; 3
, A target temperature setting device 27 for setting a target temperature to be adjusted in relation to the temperature of the outer peripheral surface of the impression cylinder 3, and a temperature difference between the temperature detected by the sensor 10 and the target temperature. Calculates the difference and issues an operation command to the hot wire heater 15
And a control device (temperature control device) 11 for controlling the heating by the control device.

That is, as shown in FIG. 3, the sheet-fed printing press for double-sided printing according to the present embodiment is close to the outer peripheral surface of the impression cylinder 3,
In addition, a hot-wire heater 15 is provided at a part of the circumferential direction of the impression cylinder 3 so as to extend along the axial direction of the impression cylinder 3, whereby the entire outer peripheral surface of the impression cylinder 3 is quickly heated to a uniform temperature and a uniform temperature. It is configured to be. The sheet-fed printing press for duplex printing according to the present embodiment has a sensor 10 for detecting the surface temperature of the impression cylinder 3.
And a temperature control controller 11 is provided. The hot-wire heater 15 is configured so that the surface temperature becomes uniform in the axial direction of the impression cylinder 3, and the sensor 10 uses the detected value as an electric signal as a temperature control controller 11.
Can be sent to

In the temperature control controller 11, printing ink temperature data of the lower surface of the sheet 12 (the sheet surface in contact with the impression cylinder 3) obtained by experiments and running while rolling on the impression cylinder 3 or the impression cylinder 3 A signal of printing ink temperature data sent from an ink temperature detection sensor 13 disposed on the upstream side close to the impression cylinder 3 to measure the temperature of the ink 16 on the surface of the sheet 12 contacting with the surface of the impression cylinder 3 A signal from the sensor 10 for detecting the temperature is input. Thus, the temperature control controller 11 is configured so that the output of the above-described hot-wire heater 15 can be appropriately controlled by calculating the input data.

For this purpose, the temperature control controller 11 includes a target temperature setting device 27 and an arithmetic control device 28,
The sensor 3 and the ink temperature detection sensor 13 are configured to control the surface temperature of the impression cylinder 3 to a predetermined temperature relatively to the temperature of the ink 16 immediately before contacting the impression cylinder 3. I have. In addition, FL shows the floor surface in FIG.

In the sheet-fed printing press for double-sided printing of the present embodiment configured as described above, the calculated temperature data (temperature difference) is fed back to the hot-wire heater 15 via the temperature control controller 11. Thus, the output of the hot wire heater 15 is controlled, and the temperature of the outer peripheral surface of the impression cylinder 3 can be accurately maintained based on the set value (temperature data).

As a method for controlling the temperature of the surface of the impression cylinder 3, an ink temperature detection sensor 13 is provided via a temperature control device 11.
Various methods can be adopted, such as a method of directly matching with the temperature data from, or a method of inputting data along a general control curve substantially corresponding to the temperature data and performing simple control.

According to the sheet-fed printing press for double-sided printing of the present embodiment, the following effects can be obtained as in the first embodiment. (1) Separation state of the ink 16 on the surface of the impression cylinder 3,
In other words, the amount of the ink 16 on the printing surface remaining on the sheet 12 side and
Since the amount of transfer to the impression cylinder 3 can be balanced (stabilized) at a predetermined ratio, there is no change in color tone. (2) Since print disturbances such as a change in ink density and double fog are eliminated, print quality can be improved. (3) Since the temperature of the impression cylinder 3 can be adjusted by the hot-wire heater 15, the structure thereof is smaller than that of the first embodiment.
The size of the device can be reduced.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made without departing from the gist of the present invention. Things.

[0034]

As described above, the sheet-fed printing press for double-sided printing according to the first aspect of the present invention is provided with an impression cylinder through which a liquid for temperature adjustment flows, and provided on the impression cylinder. A rotary joint that circulates liquid inside and outside the impression cylinder, a liquid circulation device that is connected to the rotary joint and circulates the liquid, and a liquid temperature controller that is connected to the rotary joint and adjusts the temperature of the liquid. A target temperature setting device for setting a target temperature of the liquid to be controlled, and a control device for controlling operation of each device including the liquid temperature controller. For this reason, according to the sheet-fed printing press for double-sided printing of the present invention, it is possible to control the surface temperature of the impression cylinder to be a predetermined temperature with respect to the temperature of the ink printed earlier. The state of ink separation on the surface of the impression cylinder, that is, the amount of ink remaining on the preceding printing surface remaining on the sheet side and the amount of ink transferred to the impression cylinder side can be balanced (stabilized) at a predetermined ratio. Therefore, there is no change in the ink density such as a change in the color tone or the like, and there is no printing obstruction such as the double, so that the print quality can be improved.

According to a second aspect of the present invention, there is provided a sheet-fed printing press for double-sided printing according to the present invention, wherein a sensor for measuring a surface temperature of the impression cylinder is associated with the impression cylinder, and a temperature measured by the sensor. And the difference between the target value set by the target temperature setting device,
An arithmetic and control unit for issuing an operation command to the liquid temperature controller is provided. Therefore, according to the sheet-fed printing press for duplex printing of the present invention, the difference between the actual temperature of the surface of the impression cylinder and the target temperature is calculated so that the surface temperature of the impression cylinder becomes closer to the target value. Since it is possible to precisely control the print quality, the print quality can be further improved.

Further, according to a third aspect of the present invention, there is provided a sheet-fed printing press for duplex printing according to the present invention, wherein a heating means provided in proximity to the outer peripheral surface of the impression cylinder and a temperature of the outer peripheral surface of the impression cylinder are detected. A sensor, a target temperature setting device that sets a target temperature to be adjusted in relation to the temperature of the outer peripheral surface of the impression cylinder, and issues an operation command by calculating a difference between the temperature detected by the sensor and the target temperature. A control device for controlling heating by the heating means. Therefore, according to the sheet-fed printing press for double-sided printing of the present invention, it is possible to adjust the temperature of the impression cylinder by the heating means. As compared with the case, the size of the apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram illustrating a sheet-fed printing press for duplex printing according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a conceptual diagram showing a sheet-fed printing press for duplex printing according to a second embodiment of the present invention.

FIG. 4 is a conceptual diagram showing a conventional sheet-fed printing press for duplex printing.

FIG. 5 is a conceptual diagram showing a portion of an impression cylinder in the conventional sheet-fed printing press for duplex printing.

FIG. 6 is a diagram showing a relationship between a printing time and a temperature of each part in the conventional sheet-fed printing press for duplex printing.

FIG. 7 is a diagram showing the relationship between printing time and print density in the conventional sheet-fed printing press for double-sided printing.

FIG. 8 is a conceptual diagram showing an analysis of the transfer of ink to an impression cylinder in the conventional sheet-fed printing press for duplex printing, wherein the surface temperature of the impression cylinder is higher than the ink temperature of a sheet. is there.

FIG. 9 is a conceptual diagram showing an analysis of ink transfer to an impression cylinder in the conventional sheet-fed printing press for duplex printing, wherein the surface temperature of the impression cylinder is lower than the ink temperature of a sheet. is there.

FIG. 10 is a conceptual diagram showing an analysis of a transfer of ink to an impression cylinder in the conventional sheet-fed printing press for duplex printing, wherein the surface temperature of the impression cylinder is equal to the ink temperature of a sheet.

[Explanation of symbols]

 Reference Signs List 1 frame 2 bearing 3 impression cylinder 4 liquid supply pipe (water supply pipe) 5 liquid temperature controller (water temperature controller) 6 liquid circulation device (water circulation device) 7 rotary joint 8, 9 piping 10 sensor 11 control device (temperature control) Control device) 12 Sheet 13 Ink temperature detection sensor 14 Liquid (water) 15 Heating means (Hot wire heater) 16 Ink 25 Printing device 26 Reversing mechanism 27 Target temperature setting device 28 Arithmetic control device

Claims (3)

[Claims] 1. An impression cylinder through which a liquid for temperature adjustment flows through, a rotary joint provided on the impression cylinder, for flowing the liquid into and out of the impression cylinder, and a liquid joint connected to the rotary joint. A liquid circulating device that circulates the liquid, a liquid temperature controller connected to the rotary joint to adjust the temperature of the liquid, a target temperature setting device that sets a target temperature of the liquid to be controlled, and the liquid temperature controller And a control device for controlling the operation of each device including: a sheet-fed printing press for double-sided printing. 2. A sensor for measuring a surface temperature of the impression cylinder in relation to the impression cylinder, and determining a difference between a temperature measured by the sensor and a target value set by the target temperature setting device. 2. The sheet-fed printing press for double-sided printing according to claim 1, further comprising an arithmetic control unit that issues an operation command to the temperature controller. 3. A heating means provided close to the outer peripheral surface of the impression cylinder, a sensor for detecting a temperature of the outer peripheral surface of the impression cylinder,
A target temperature setting device for setting a target temperature to be adjusted in relation to the temperature of the outer peripheral surface of the impression cylinder; calculating a difference between the temperature detected by the sensor and the target temperature to issue an operation command to the heating means; A sheet-fed printing press for double-sided printing, comprising: