JPH09183211A - Printing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the viscosity of ink automatically by measuring the viscosity of ink in an ink circulating route and injecting a diluting agent into the ink. SOLUTION: The viscosity of each kind of ink 16 can be determined by measuring the falling velocity of each dropping weight 33 and comparing with standard data. When the viscosity of the ink 16 is high, the diluting agent pump 45 of a diluting agent injection apparatus 44 is actuated, and a diluting agent 43 in a diluting agent tank 42 is injected into an ink pan 12 in the arrow direction (j) to dilute the ink automatically to a set value of viscosity. Besides, the viscosity of the ink increases always during printing, and the viscosity never decreases, so that an ink viscosity measuring apparatus 31 is required only to control the viscosity of ink to decrease, eliminating the function to increase the viscosity. of ink.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing system most suitable for application to, for example, an electronic gravure printing system, and particularly belongs to the technical field of ink circulation.

[0002]

2. Description of the Related Art The applicant of the present invention has disclosed, for example,
An electronic gravure printing system of this kind has already been filed according to a prior application example such as No. 258854.

The prior application example of this electronic gravure printing system is provided with a printing machine 1 as shown in FIGS. 7 and 8, and this printing machine 1 has, for example, four plate jackets 2 Two jacket loading tables 3 and a plate material feeding / discharging device 4 for selectively loading the sheets one by one are provided. Further, the printing machine 1 is provided with a paper feed tray 6 on which cut printing paper 5 is stacked and a paper discharge tray 18 on which printed printing paper 5 is stacked. Two printing units 8 for printing each of two colors out of four colors such as magenta, yellow and black
A printing paper circulating mechanism 7 for circulating the printing paper 5 is provided in the printing unit 8 or the printing unit 8.

In the four plate material jackets 2,
As shown in FIG. 9, image data 10 such as color photographs of different colors such as cyan, magenta, yellow, and black are engraved (engraved) on the surface by unevenness of the submicron order, and the plate materials 9 are respectively stored. Has been done.

Further, as shown in FIG. 8, two printing units 8 for each color are provided with one plate cylinder 11 and one impression cylinder 15, respectively.
And two ink pans 12 each, a total of four ink pans 12, an ink roll 13, a doctor blade 14, etc. are provided, and four color water-based inks 16 such as cyan, magenta, yellow, and black are provided in the ink pans 12 for each color. Is being supplied. Each of the two ink pans 12, the ink rolls 13, the doctor blades 14 and the like is configured to be switched by two colors for each one plate cylinder 11.

In the electronic graphia printing system,
As shown in FIG. 7, a printing machine including four plate material jackets 2 in which image data 10 such as a color photograph is plate-made by color in the plate making process The two jacket loading tables 1 are selectively loaded horizontally from the direction of arrow a. Then, each plate material 9 is removed from each plate material jacket 2 by each plate material feeding / discharging device 7.
Is automatically pulled out in the direction of arrow a,
As shown in FIG. 11, it is automatically wound around the outer periphery of the plate cylinder 11 of each printing unit 8.

Therefore, the printing paper 5 in the paper feed tray 6 shown in FIG. 8 is supplied by the printing paper circulation mechanism 7 to the impression cylinders 15 of the two printing units 8 so as to be sequentially circulated, and shown in FIG. Such printing is performed, and the printed printing paper 5 is discharged to the paper discharge tray 18 by the printing paper circulation mechanism 7.

At this time, as shown in FIG. 9, in each printing unit 8, each ink roll 13 is brought close to the surface of each plate 9 while rotating each plate cylinder 11 at high speed in the direction of arrow b.
Is rotated at high speed in the direction of arrow c in synchronism with each plate cylinder 11, and the ink 16 for each color in the ink pan 12 is applied to the unevenness of the image data 10 for each plate 9 by each doctor blade 14. Unnecessary ink 16 is scraped off in the direction of arrow d. Then, the printing paper 5 is transferred to each plate material 9 by each impression cylinder 15 which is rotated at a high speed in the direction of arrow e in synchronization with each plate cylinder 11.
The image 17 for each color is sequentially printed on the printing paper 5 at high speed by the image data 10 for each color such as a photograph of each plate material 9 while being pressure-bonded to the surface of the plate material 9 at a high speed.

Then, the printing paper 5 is replaced by two printing units 8
And the printing units 8
While sequentially switching the two ink pans 12 for each color for each plate cylinder 11, the operation of loading two of the four plate material jackets 2 shown in FIG. 7 and the operation of printing shown in FIG. 9 are repeated. As described above, the image data 2 for each color such as a photograph of each plate material 9 is sequentially overprinted to obtain an image 17 such as a color photograph in which four colors such as cyan, magenta, yellow, and black are combined. It is possible to print a color printed matter printed on a sheet of printing paper 5. However, one-color printing, two-color printing, three-color printing, and printing of four or more colors are also possible,
The number of printing steps will increase or decrease according to the number of colors to be printed.

[0010]

By the way, in this electronic gravure printing system, it is very important to keep the viscosity of the water-based ink 16 constant, and when the ink viscosity becomes too thick, it is printed on the printing paper 5. Ink 1 on the image 17
A large amount of dirt is apt to be generated due to dragging of No. 6 and the like. Also,
If the ink viscosity becomes too thin, the ink 16 dries too quickly, and the sharpness of the image 17 printed on the printing paper 5 is likely to be significantly impaired.

However, conventionally, no means for automatically detecting the ink viscosity and automatically controlling the ink viscosity has been taken, and the printing operator calls the Zan cup at regular intervals. With a viscometer
The ink viscosity was manually measured, and the diluent was poured into the ink in a metered amount to manually control the ink viscosity.

However, such a manual operation of controlling the ink viscosity is very inefficient, and the variation in the ink viscosity is so large that a high quality image cannot be printed stably. there were.

The present invention has been made to solve the above problems, and an object thereof is to provide a printing system capable of automatically controlling the ink viscosity.

[0014]

A printing system of the present invention for achieving the above object is to measure the viscosity of ink in an ink circulation path formed between an ink pan and an ink tank by a viscosity measuring means. A means for injecting a diluent into the ink is provided based on the measured value of the viscosity measuring means.

The printing system of the present invention configured as described above automatically measures the viscosity of the ink in the ink circulation path between the ink pan and the ink tank, and dilutes it in the ink as necessary. The viscosity of the ink can be automatically controlled by automatically injecting the agent.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment in which the present invention is applied to a printing machine of an electronic gravure printing system will be described below with reference to FIGS. The same components as those in FIGS. 7 to 9 are denoted by the same reference numerals, and the description will not be repeated.

[Description of Ink Circulation Device] First, as shown in FIG. 1, the ink circulation device 21 is composed of a plastic pipe, and an ink supply path 23 connecting the ink tank 22 and the ink pan 12 and ink discharge. Route 2
4, an ink pump 25 is arranged on the upper side of the ink supply path 24, and a filter 26 is arranged on the lower side. The ink discharge path 24 is provided in the ink pan 12.
Is connected to the ink tank 22.

When the ink pump 25 is operated during printing, the ink 16 in the ink tank 22 is removed.
Is sucked up by the ink supply path 23, passes through the filter 26 on the way, and impurities in the ink 16 are removed. Then, the ink 16 is moved upward in the ink supply path 23 in the direction of arrow g. The ink is supplied into the ink pan 12.

Then, the ink 16 in the ink pan 12 is returned from the bottom to the inside of the ink tank 22 by dropping in the ink discharge path 24 in the direction of arrow h. Then, due to the circulation operation of the ink 16 in the directions of the arrows g and h between the ink pan 12 and the ink tank 22, the amount of the ink 16 in the ink pan 12 is constant (as shown in FIG. The ink 16 is kept in a certain amount).

As described above, the ink circulation device 21 is provided for four colors of the ink 16 such as cyan, magenta, yellow and black.

Next, as shown in FIGS. 1 and 2, ink is provided above and below the vertical path portion in each ink supply device 23 in the ink circulation device 21 for four colors such as cyan, magenta, yellow and black. Valves 27, 2
8 are arranged, and an ink viscosity measuring device 31 for four colors such as cyan, magenta, yellow and black is arranged between them.

That is, a total of four vertical ink viscosity measuring paths 32 are formed between the upper and lower ink valves 27 and 28 in the ink supplying paths 23 for the four colors, and these ink viscosity measuring paths 32 are provided. A drop weight 33, which is an ink viscosity measuring means, is housed inside each of the. Then, between the pair of upper and lower ink valves 27, 28 of these four ink viscosity measuring paths 32,
Sensor positions P ₂ and P ₃ are set in two places, upper and lower,
A pair of upper and lower metal sensors 34 and 35, which are sensors, are attached to these sensor positions P ₂ and P ₃ .

At this time, as shown in FIG. 2A, the four ink viscosity measuring paths 32 are arranged at the upper and lower sensor positions P ₂ ,
A pair of upper and lower holders 38 and 39 are bundled in a cylindrical shape at P ₃ , and a pair of upper and lower ring-shaped metal sensors 34 are provided on the outer circumferences of the four ink viscosity measuring paths 32 at the inner circumferences of the holders 38 and 39. , 35 are arranged. Therefore, the pair of upper and lower metal sensors 34 and 35 are configured to be shared by all four ink viscosity measuring paths 32.

As shown in FIGS. 3A and 3B and FIG. 4, the drop weight 33 includes a main shaft 33a composed of a vertical screw shaft, and an umbrella just fixed to the upper end of the main shaft 33a. The rotating blade 33b is formed by a rotating blade 33b having a shape that opens, and a weight 33c fixed to the lower end of the main shaft 33a. The rotating blade 33b is composed of a pair of upper and lower nuts 3.
It is fixed to the upper end of the main shaft 33a by 3d. The entire drop weight 33 is made of a metal such as a stainless material having a corrosion resistance.

Then, as shown in FIGS. 1 and 2, a pair of upper and lower ink valves 2 of the four ink viscosity measuring paths 32.
Between 7 and 28, a position above the upper sensor position P ₂ and
Stopper positions P ₁ and P ₄ are set at two positions below the lower sensor position P ₂ , and stainless steel material is provided in each ink viscosity measuring path 32 at each stopper position 36 and 37 in FIG. 3C. Stopper pins 36 and 37 made of plastic or the like are attached.

In this embodiment, as shown in FIG.
And the total length which is the length of the drop weight 33 in the vertical direction.
H is set to about 15 mm and the upper stopper position
P₁And the upper sensor position P_Two Interval L with₁ Is about 96 mm
The vertical sensor position P is set _Two , P_Three Interval L_Two Is about 2
78mm, lower sensor position P_Three And bottom
Par position P_Four Interval L with_Three Is set to about 36 mm
You.

As shown in FIG. 1, each of the four color ink circulation devices 21 is provided with a diluent injection device 41. These diluent injection devices 41 include a diluent tank 42 and a diluent tank 42 thereof. A diluent pump 45 for injecting the internal diluent 43 into each of the ink pans 12 for four colors through a diluent injection path 44 formed of a plastic pipe.

[Explanation of Ink Viscosity Measurement and Ink Dilution Operation] Next, referring to the flow chart of FIG. 5 with reference to FIGS. 1 to 4, the viscosity measurement operation of the ink 16 and the dilution of the ink 16 based on the measured value. The operation will be described.

First, as described above, the ink circulation device 2
While the ink circulation operation in which the ink pump 25 of No. 1 is operated to circulate the ink 16 between the ink pan 12 and the ink tank 22 in the directions of arrows g and h, the ink 16 passes through each ink viscosity measurement path 32. It is constantly elevated in the direction of arrow g from below to above.

Then, each drop weight 33 is lifted in the ink viscosity measuring path 32 to the upper stopper position P _{1 in the} direction of the arrow g by the thrust due to the upward flow of the ink 16, and abuts on the upper stopper pin 36 to stop. Has been done.

Next, when measuring the ink viscosity, the ink pump 25 is stopped and at the same time the upper and lower ink valves 2 are
By closing 7, 28, the flow of the ink 16 in each ink viscosity measuring path 32 is stopped.

Then, the drop weight 33 in each ink viscosity measuring path 32 naturally falls in the direction of the arrow g'by its own weight.

At this time, each of the drop weights 33 falls at a stable speed while rotating about the main shaft 33a in the direction of arrow i in FIG.

Furthermore, each drop weight 33 falls in the direction of arrow g'in the run-up section of the interval L ₁ set between the upper stopper position P ₁ and the upper sensor position P ₂ in each ink viscosity measuring path 32. While dropping, the drop speed of each of the drop weights 33 becomes stable.

When each drop weight 33 passes through the upper sensor position P ₂ of each ink viscosity measuring path 32, the upper metal sensor 34 detects and the detection signal is output to the microcomputer (CPU) 52.

Then, after a lapse of about 2 seconds, each of the drop weights 33 is connected to each of the ink viscosity measuring paths 3.
When the drop weights 33 drop to the lower sensor position P _{3 in the} direction of the arrow g ′ and pass through the lower sensor position P ₃ , the lower metal sensor 34 detects and the detection signal is output to the microcomputer 52. It

After this, each drop weight 33 drops to the lower stopper position P ₄ of each ink viscosity measuring path 32, contacts the lower stopper pin 37, and stops.

Then, the microcomputer 52 measures the passage time of the drop weights 33 between the upper metal sensor 34 and the lower metal sensor 35 of each drop weight 33 due to natural drop, and determines the drop speed of the drop weights 33. Calculate Then, the falling speed is compared with reference data preset in the ROM circuit 51.

At this time, if the viscosity of the ink 16 is high, the drop speed of the drop weight 33 becomes slow, and the ink 16
If the viscosity is low, the drop speed of the drop weights 33 becomes fast. Therefore, the viscosity of each ink 16 can be measured by measuring the drop speed of each drop weight 33 and comparing it with the reference data.

When the viscosity of each ink 16 is high, the diluent pump 45 of the diluent injection device 44 is actuated to move the diluent 43 in the diluent tank 42 into the ink pan 12.
The ink viscosity is automatically diluted to the set value by injecting from the direction of arrow j.

During printing, the ink viscosity is constantly increasing,
Since the ink viscosity never drops, the ink viscosity measuring device 31 only needs to perform control for lowering the ink viscosity, and the function for increasing the ink viscosity is unnecessary.

In the actual ink viscosity measuring operation, the viscosities of the inks 16 for four colors are individually and sequentially measured in each of the four ink viscosity measuring paths 32. 8 metal sensors in total 3
4, 35 are required.

However, as shown in FIG. 2A, the ink viscosity measuring paths 32 for the four colors are bundled in a cylindrical shape, and a ring shape is formed on the outer circumference of the pair of upper and lower sensor positions P ₁ and P _3. Since the metal sensors 34 and 35 of 4 are arranged, the viscosity of the ink 16 for four colors can be measured by using only two metal sensors 34 and 35, and the structure can be simplified and the cost can be reduced. I was able to. Even if the viscosities of the inks 16 for the four colors are individually and sequentially measured, the diluent 43 is individually injected into the ink tank 12 after the ink viscosity is measured, and the ink 1
When diluting 6, the time is required until the diluent 43 is uniformly mixed in the entire ink 16, so even if the individual metal sensors 34 and 35 for four colors are provided, the inks for four colors The viscosity measurement operation cannot be performed very efficiently.

The drop weight 33, which constitutes the ink viscosity measuring means, has a rotating blade 33b, which rotates at a stable drop speed in the ink viscosity measuring path 32 while rotating by the rotating blade 33b. Since the ink can drop naturally, it is possible to obtain an accurate change in the falling speed corresponding to the change in the ink viscosity, the error in measuring the ink viscosity is very small, and the ink viscosity can be accurately measured.

Incidentally, FIG. 6 is a graph showing an experimental value of the relationship between the drop time of the drop weight 33 and the Zahn value which is the value of the ink viscosity. When the drop time of the drop weight 33 is 2.02 seconds. The Zahn value was 16.0 s.

When actually measuring the viscosity of the ink, it is usually measured 5 times, and when x ₁ ≧ x ₂ ≧ x ₃ ≧ x ₄ ≧ x ₅ , x ₃ is taken as the measured value, and the measured value and the ROM circuit 51 According to the magnitude of the difference, the diluent pump 45 is operated by the microcomputer 52 to automatically control the injection amount of the diluent 43 into the ink pan 12 according to the magnitude of the difference. In this way, the ink viscosity is converged to the set value.

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 can be made based on the technical idea of the present invention.

For example, in the above-described embodiment, the metal drop weight 33 is used, and the drop velocity (fall time) of the drop weight 33 is measured by the metal sensors 34 and 35. It is also possible to use a non-metal having a heavier specific gravity, to embed a magnet in the drop weight 33, and to measure the falling speed (falling time) using a magnet sensor.

The printing system of the present invention configured as described above has the following effects.

According to the first aspect, the viscosity of the ink is automatically measured in the ink circulation path between the ink pan and the ink tank, and the diluent is automatically injected into the ink when necessary. Since the ink viscosity can be automatically controlled, the ink viscosity control work can be performed with high efficiency, the variation in ink viscosity can be minimized, and high-quality images can be printed stably. be able to.

According to a second aspect of the present invention, an ink viscosity measuring path is formed vertically in the middle of the ink circulation path so that the ink flows from the lower side to the upper side, and valves disposed above and below the ink viscosity measuring path. The ink is stored in the ink viscosity measurement path, and is pushed up to the ascending position by the ink while the ink is flowing from the lower side to the upper side in the ink circulation path. A drop weight that is dropped in the measurement path from its raised position to a lowered position by its own weight, a sensor that detects the drop velocity due to the weight of the drop weight, and a means for injecting a diluent into the ink based on the detection value of the sensor. Since it is equipped with, the ink viscosity can be measured during the ink circulation, and the ink viscosity can be automatically controlled during the printing operation. It allows the fast convergence to the value.

According to the third aspect of the present invention, the drop weight is provided with the rotary vane and the weight so that the drop weight is dropped at a stable speed while rotating. Therefore, it is possible to measure the ink viscosity with high accuracy. Highly accurate automatic viscosity control.

According to a fourth aspect of the present invention, a plurality of ink viscosity measuring paths accommodating drop weights are provided for each color of ink, the plurality of ink viscosity measuring paths are bound together, and the plurality of bound ink viscosity measuring paths are combined. Since the sensor is arranged so as to surround the outer circumference, the structure can be simplified and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an ink circulation device, an ink viscosity measurement device, and a diluent injection device in an embodiment in which the present invention is applied to an electronic gravure printing system.

FIG. 2 is a cross-sectional plan view for explaining the ink viscosity measuring device and a partially cut-away side view developed and shown.

FIG. 3 is a sectional side view and two sectional plan views of an ink viscosity measuring path.

FIG. 4 is a perspective view of a drop weight that is an ink viscosity measuring unit.

FIG. 5 is a flow chart for explaining the operations of ink viscosity measurement and diluent injection.

FIG. 6 is a graph showing experimental values of the relationship between the drop time of the drop weight and the Zahn value of the ink.

FIG. 7 is a side view of the printing machine.

FIG. 8 is a diagram illustrating a printing unit of the printing press and a method of circulating the printing paper.

FIG. 9 is a partially cutaway side view illustrating the printing operation of the printing unit.

[Explanation of symbols]

 1 Printing Machine 12 Ink Pan 13 Ink Roll 14 Doctor Blade 16 Ink 21 Ink Circulation Device 22 Ink Tank 23 Ink Supply Route 24 Ink Discharge Route 25 Ink Pump 26 Filter 27, 28 Ink Valve 31 Ink Viscosity Measuring Device 32 Ink Viscosity Measuring Route 33 Drop Weight (ink viscosity measuring means) 34, 35 Metal sensor (sensor) 36, 37 Stopper pin 38, 39 Holder (bundling means) 41 Diluent injection device 42 Diluent tank 43 Diluent 44 Diluent injection path 45 Diluent pump

Claims (4)

[Claims] 1. A plate cylinder having a plate material wound around an outer periphery thereof, an ink pan for applying a predetermined amount of ink to the surface of the plate member, an ink unit including an ink roll and a doctor blade, and an ink pan, In a printing system in which an ink circulation path including a pump and a filter is formed between the ink tank and the ink tank, means for measuring the viscosity of the ink in the ink circulation path, and the measurement value of the viscosity measurement means A printing system comprising means for injecting a diluent into the ink. 2. A plate cylinder having a plate material wound around the outer periphery thereof, an ink pan for applying a fixed amount of ink to the surface of the plate member, an ink unit comprising an ink roll and a doctor blade, and an ink pan, In a printing system in which an ink circulation path including a pump and a filter is formed between the ink tank and the ink tank, an ink is formed vertically in the middle of the ink circulation path so that the ink flows from the lower side to the upper side. Viscosity measurement path, valves arranged above and below the ink viscosity measurement path, and accommodated in the ink viscosity measurement path, and rises by the ink while flowing from below to above in the ink circulation path. It is pushed up to the position, and by closing the pair of upper and lower valves, it descends from the ascending position in the ink viscosity measurement path by its own weight. A drop weight that is dropped to a position, a sensor that detects a drop speed of the drop weight due to its own weight, and a means that injects a diluent into the ink based on a detection value of the sensor. Printing system. 3. The printing system according to claim 2, wherein the drop weight is composed of a rotating blade at the upper end and a weight at the lower end. 4. A plurality of ink viscosity measuring paths accommodating the drop weights are provided for each color of ink, and the plurality of ink viscosity measuring paths are bundled into a cylindrical shape,
3. The printing system according to claim 2, wherein the sensor is arranged so as to surround the outer circumference of the entire bounded plurality of ink viscosity measurement paths.