JP2594491Y2 - Spray dampening water supply device for offset printing press - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray dampening water supply apparatus which can be suitably applied to an offset printing press, and in particular, there is no clogging of a nozzle hole of the dampening water supply apparatus, and the stability is remarkable. The present invention relates to a dampening solution supply device for an offset printing machine that can be maintained for a long period of time.

[0002]

2. Description of the Related Art A printing plate used for lithographic printing (usually called offset printing) has an image portion and a non-image portion formed on the same plane. The image area is lipophilic (hydrophobic) and has high acceptability for oil-based inks.
Treated to be unacceptable for water,
The non-image area is hydrophilic (oleophobic), is highly receptive to water, and is treated so as not to accept oily ink. In offset printing using a lithographic printing plate subjected to such processing, water (fountain solution) is first applied to a hydrophilic non-image portion to form a uniform and thin film of water on the printing plate. It is necessary to let

In offset printing, after a dampening solution is applied to a non-image area on a printing plate, it is necessary to apply oil-based ink to the printing plate before the dampening solution film does not dry. In order to maintain quality, the balance between the fountain solution and the oil-based ink on the printing plate is extremely important. If the supply amount of the dampening water is increased more than necessary, problems such as emulsification of the oil-based ink occur, and printing becomes impossible. On the other hand, if the amount of dampening water is too small, a uniform water film is not formed on the non-image area, or the ink dries until ink is applied.

[0004] Therefore, the printing operator must always be careful to apply the minimum necessary dampening solution uniformly to the printing plate. For this reason, in recent years, a spray-type dampening water supply device has been put to practical use. The spray method includes a one-fluid method in which pressurized dampening water is sprayed from a spray nozzle, and a two-fluid method in which dampening water and compressed air are mixed and sprayed from a spray nozzle. The former is adjusted by the opening and closing time of an electromagnetic valve provided upstream of the spray nozzle, and the latter is adjusted by the operating time of a pump for supplying dampening water.

[0005]

However, in the dampening solution supply device of the spray type, when the dampening solution is not sprayed from the spray nozzle, the opening of the nozzle is in contact with the outside air. Dissolved components in the fountain solution remaining in the fountain solution are concentrated to increase the viscosity, and become supersaturated and precipitate, thereby causing clogging at the nozzle opening. Further, there are scattering of printing ink and scattering of paper powder from outside, which also causes clogging of the opening. On the upstream side of the nozzle,
A filter is provided and impurities in the piping are filtered. However, it is conceivable that impurities finer than the eyes of the filter become nuclei, and dissolved components in the dampening water precipitate to cause clogging. If clogging occurs in the nozzle opening, the dampening solution jetting becomes worse, the spray pattern changes, and it becomes impossible to supply uniform dampening solution to the printed matter, and streak-like dirt is generated on the printed matter, and printing is performed. There is a problem that quality is deteriorated.

Japanese Patent Application Laid-Open No. 53-50834 discloses a method of preventing the nozzle opening from being clogged by using an ultrasonic oscillator for the nozzle opening of the ink jet recording apparatus. A method has been proposed in which ultrasonic waves from an ultrasonic oscillator are focused on an opening from the outside at the time of injection to eliminate nozzle clogging. However, this method cannot detect the ink ejection failure, and therefore, a time device for operating the ultrasonic oscillator in order to stop the ejection and operate the ultrasonic oscillator at regular intervals determined by experience. There is a problem that must be stopped.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a spray dampening water supply apparatus for an offset printing press which eliminates a partial supply failure of a dampening water and continuously provides high printing quality.

[0008]

According to the present invention, there is provided a spray dampening water supply device for an offset printing press, comprising: an ultrasonic oscillator for cleaning a hole of each nozzle in each spray nozzle; Detecting means for detecting dampening solution sprayed on the circumference of a predetermined spray angle, and control means for driving an ultrasonic oscillator, wherein the electromagnetic wave of the spray dampening water supply device for the offset printing press is provided. The signal from the valve drive control circuit or the motor drive control circuit of the metering pump device is a signal for supplying dampening water, and the signal from the detection means is a signal that does not detect dampening water spray. The control means drives the ultrasonic oscillator when the spraying dampening solution is supplied to an offset printing press.

[0009]

According to the present invention, an ultrasonic oscillator for cleaning a hole of each nozzle in each nozzle and a dampening solution sprayed on a circumference of a predetermined spray angle on a dampening solution spray side are detected. And a control means for driving the ultrasonic oscillator. The control unit drives the ultrasonic oscillator by a signal from the spray detection unit and a signal from the solenoid valve drive control circuit of the spray dampening solution supply device for the offset printing press or the motor drive control circuit of the metering pump device. By doing
The ultrasonic oscillator vibrates, and the ultrasonic waves reach the nozzle holes, and the nozzles can be clogged by the action of the ultrasonic waves. That is, the output from the spray detection means when the dampening water does not spread in the form of mist due to clogging of the nozzle hole, and the solenoid valve drive control circuit or the motor of the metering pump device when the dampening water is supplied. When the signals supplying the dampening solution from the drive control circuit are combined, the control means sends a signal to the ultrasonic oscillator to drive the ultrasonic oscillator. Further, when the clogging of the nozzle hole is removed and the dampening solution spreads in a mist, the output signal from the spray detecting means stops and the driving of the ultrasonic oscillator is stopped.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described in more detail with reference to the spray dampening water supply apparatus for an offset printing press according to the present invention.

FIG. 1 is a perspective view showing an example of the configuration of an offset printing press 1 having a spray dampening water supply device according to the present invention.

The printing plate 40 is wound around a straight cylindrical cylinder 41. The cylinder 41 is fixed to a rotating shaft 42, and a pulley 43 is fixed to one end of the rotating shaft 42 in the axial direction. Since the rotation of the printing plate 40, the cylinder 41, and the rotation shaft 42 are integrated, the pulley 43 fixed to the rotation shaft 42 has the same rotation speed as the rotation of the printing plate 40. The rotation of the pulley 43 is transmitted to the stretched belt 44 and transmitted to the pulley 45. The pulley 45 is fixed to a rotation shaft 46 of a speed detector 47, and rotation of the pulley 45 is transmitted to the speed detector 47. The output from the speed detector 47 is input to the solenoid valve driving control circuit 51 via the conductor S. The control circuit 51 for driving the solenoid valve includes, in addition to the printing speed, an image density input in advance,
A predetermined amount of dampening water is opened and closed by opening and closing a solenoid valve 34, which will be described later, by a memory 27 which is determined in advance in accordance with printing conditions such as image coverage, type of printing machine, type of paper, type of ink, and environment. Is sprayed on the printing plate 40.

In the printing, multi-color printing is performed by one printing machine. Therefore, four or more printing plates 40 are usually provided. However, in FIG. 1, there are two printing plates for simplicity of illustration. FIG. Further, there are an example (A) of supplying dampening water directly to the printing plate 40 from the spray nozzle 31 and an example (B) of supplying dampening water via one or a plurality of dampening rollers 48. Each of them is shown in FIG. 1, and even if the dampening solution is supplied to one printing press entirely in the example (A) or supplied all in the example (B), as shown in FIG. ) And Example (B) may be used in combination. That is, the supply of the dampening solution to the printing plate 40 may be direct or indirect, and a certain amount of dampening solution is supplied to the printing plate 40 according to the speed and printing conditions. Good quality printing is possible.

The dampening water 3 is stored in the storage container 2, pressurized by a pump 5 via a pipe 4, and sent to a pipe 6. A pressure gauge 7 is connected to the pipe 6, and the pressure of the dampening solution discharged from the pipe 6 by the pump 5 is measured.
The pressure of the dampening solution pumped through the pipe 6 is, for example, 7 kg.
/ Cm ² .

The dampening solution from the pipe 6 is supplied to a pipe 9 via an opening / closing valve 8 provided for each printing plate, and after a foreign substance or the like is removed by a filter 10 to be cleaned, the pressure is reduced. The pressure is reduced by the regulating valve 11. This pressure regulating valve 11
Is connected to a pipe 13, and the pressure in the pipe 13 is measured by a pressure gauge 12.
Is measured by The pressure of the dampening solution in the pipe 13 is, for example, about 5 to 6 kg / cm ² . A commercially available regulator can be used for the pressure regulating valve 11,
For example, in the flow rate range of 0 to 300 ml / min, the pressure on the outlet side is kept substantially constant even if the flow rate fluctuates. When the pressure on the outlet side exceeds the adjustment pressure, the safety valve opens to adjust the pressure on the outlet side. It is configured to keep it below pressure.

The dampening solution from the pipe 13 thus depressurized is guided to the pulsation adjusting tank 14. As the pulsation adjusting tank 14, a commercially available accumulator can be used. The upper part of the pulsation adjusting tank 14 has an air chamber partitioned by a partition, and the lower part is filled with a dampening solution under pressure. The fountain solution guided from the pipe 13 to the pulsation adjusting tank 14 pulsates, for example, at 5 to 6 kg / cm ² and does not have a constant pressure. The pressure of the dampening solution guided from the pipe 13 to the pulsation adjusting tank 14 is, for example, 6 kg /
At cm ^2, the pressure is absorbed by the buffering action of the air partitioned by the partition. Therefore, the pulsation adjusting tank 14
The fountain solution coming out of the tank and led to the line 15 has a pressure of 5.5 k.
g / cm ² . On the other hand, the pressure of the dampening solution guided from the pipe 13 to the pulsation adjusting tank 14 is, for example, 5 kg / c.
At m ² , the air is pressurized by the air partitioned by the partition. Therefore, the pressure of the dampening solution that has exited from the pulsation adjusting tank 14 and has been guided to the conduit 15 increases to 5.5 kg / cm ² .

FIG. 2 is a system diagram showing the entire configuration of an embodiment of the spray dampening water supply device for an offset printing press according to the present invention. FIG. 3 is a cross-sectional view showing the configuration of one spray device 30. FIG. The dampening solution having a constant pressure is supplied to the pipe 1
After that, it is supplied to the manifolds 16a to 16d built in the spraying devices 30a to 30d. Manifold 16a
Fountain solution supplied to the spray nozzles 31a to 3d
The fountain solution is guided to 1d, and fountain solution is sprayed onto the printing plate 40 in a mist form from the holes 36a to 36d of the nozzles 31a to 31d at a pressure of 5.5 kg / cm ² .

Each spraying device 30 is provided with an electromagnetic valve 33 that is operated by an electromagnet section 34. When the electromagnetic valve 33 closes the water inlet 38, dampening water is not supplied to the injection nozzle 31; The fountain solution is not discharged in the form of a mist from the hole 36. The electromagnetic valves 33a to 33d provided in the spray devices 30a to 30d may operate in the same tone, or may operate with a shift at certain intervals. Further, by changing the ratio of the opening time and the closing time of the water inlets 38a to 38d of the solenoid valves 33a to 33d, the injection amount of the dampening water from the injection nozzles 31a to 31d can be individually controlled, and can be controlled for a certain time. Solenoid valves 33a-33 within
By changing the number of times of opening and closing the water inlets 38a to 38d of d, it is possible to individually control the injection amount of the dampening solution from the injection nozzles 31a to 31d. A return pipe 18 is connected to each manifold 16, and excess dampening water returns to the storage container 2 via the orifice 17. Orifice 17
In order to prevent the pressure of the dampening solution in the manifold 16 from dropping rapidly, a narrow overflow portion is provided so as to flow at a flow rate equal to or less than a certain value. Further, the orifice 17 may be a pipe in which a part of the pipe 18 is narrowed or a cock for adjusting the pipe diameter. The pipe 18 has a smaller pipe diameter than the pipes 9, 13, 15 to prevent a pressure drop. The pipe 18 also has a purpose of facilitating cleaning when the flow of the dampening solution is reduced due to entry of foreign matter or the like into the pipes 9, 13, 15 and the manifold 16 or generation of foreign matter.

As shown in FIG. 2, the spraying devices 30a to 30d have a spraying device 30a connected to a pipe 15 and a spraying device 30b, 30c, 30d connected in series.
d may be connected to the return line 18, and as shown in FIG. 1, the spray devices 30a to 30d are respectively connected in parallel to the inlet line 19a.
19d and outlet lines 20a to 20d
And the line 15 may be connected to the return line 18 via the orifice 17, or the spray devices 30a to 30d may be integrated. In this embodiment, four spray devices 30a to 30d are connected to one printing plate 40. However, the number of spray devices 30 for each printing plate 40 is the length of the printing plate 40. Can be changed by
It is also different.

Each spraying device 30 includes a main body 35 and an electromagnet section 3.
4 and a nozzle 31, and a dampening solution at a constant pressure, for example, 5.5 kg / cm ² is supplied from the inlet pipe 19 to the main body 3.
5 enters the manifold 16. The main body 35 has a solenoid valve 33
The solenoid valve 33 is connected to an armature 34C that operates by an electromagnetic force. Armature 34C
Is a coil 34A for generating an electromagnetic force in the electromagnet section 34.
A spring 34B is connected to the side opposite to the side to which the electromagnetic valve 33 is connected, and the spring 34B is fixed to the inner wall of the electromagnet section 34. When electricity is passed through the conducting wire EE leading to the electromagnet section 34, an electromagnetic force is generated in the coil 34A, and the armature 34C is raised in the direction of the arrow A and moves while pressing the spring 34B. The electromagnetic valve 33 fixed to the armature 34C moves in the same direction as the armature 34C, and is in the state shown in FIG. When the energization of the conducting wire EE of the electromagnet section 34 is stopped, the electromagnetic force generated in the coil 34A disappears, and the armature 34C is driven by the force of the spring 34B.
The electromagnetic valve 33 fixed to the armature 34C is pushed down in the direction of the arrow A, and the solenoid valve 33 also moves in the same direction as the armature 34C, and closes the water inlet 38 provided in the main body 35. A nozzle 31 is provided near the printing plate 40 of the main body 35. Between the water inlet 38 and the nozzle 31, an ultrasonic oscillator 39 is attached to the wall of the main body 35 via a vibration insulator 37 so as to focus on the hole 36 of the nozzle 31. The ultrasonic oscillator 39 is electrically connected by a conductor AA, and is connected to an ultrasonic generating circuit 52 of a controller 50.
When the solenoid valve 33 closes the water passage 38, the dampening water in the manifold 16 is not supplied to the nozzle 31 and the hole 3
6, the dampening water in the manifold 16 passes through the water inlet 38 to the nozzle 31 and is sprayed from the hole 36 when the solenoid valve 33 is separated from the water inlet 38. The ultrasonic oscillator 39 comes into contact with the dampening solution only when the electromagnetic valve 33 is separated from the water inlet 38 and the dampening solution flows into the nozzle 31 with a constant pressure, and at this time, the ultrasonic oscillator 39 can vibrate. It is electrically controlled so that

The dampening water passes through the hole 36 of the nozzle 31
For example, it is atomized at a pressure of 5.5 kg / cm ² . When there is no foreign matter in the hole 36 of the nozzle 31 and the dampening solution passes smoothly, the spray angle becomes α degrees. However, if a foreign substance is present in the hole 36 of the nozzle 31 and it becomes difficult for the dampening solution to pass through, the spray angle becomes narrow and the spray angle becomes, for example, β degrees. When the spray angle is α degrees, detection means for detecting the presence of the dampening solution, for example, a detection rod 32 composed of an infrared sensor, a dew condensation sensor, a microswitch, etc., detects the dampening solution sprayed at the angle α degrees. It is installed on the circumference of a predetermined spray angle on the fountain solution spray side as much as possible. Hole 3 of nozzle 31
When 6 is clogged with foreign matter and the spray angle becomes β degrees, the dampening solution does not reach the detection rod 32 that detects the dampening solution. Therefore, a signal that the hole 36 of the nozzle 31 is clogged with foreign matter is sent from the detection rod 32 to the controller 50 via the conducting wire M. On the other hand, if the dampening water pressure is higher than a certain level at the nozzle 31 when the solenoid valve 33 is separated from the water inlet 38 and the nozzle 31 is connected to the controller 50 via the conducting wire M ′.
When the two signals are combined, the spray detection circuit 53 of the controller 50 is activated, whereby the ultrasonic generator 39 connects the lead A to the ultrasonic oscillator 39.
, And ultrasonic waves are generated from the ultrasonic oscillator 39 toward the hole 36 of the nozzle 31. The ultrasonic vibration travels through a dampening solution existing at a constant pressure inside the nozzle 31 to reach the hole 36 of the nozzle 31, and vibrates and removes foreign matter in the hole 36. When the foreign matter in the hole 36 of the nozzle 31 is removed, the dampening solution returns to the injection angle α degrees, and the presence of the dampening solution is detected by the detection rod 32. When the presence of the dampening solution is detected by the detection rod 32, a signal confirming the presence of the dampening solution is transmitted to the spray detection circuit 53 through the conductor M, further transmitted to the ultrasonic wave generation circuit 52, and transmitted to the ultrasonic oscillator 39. Is cut off, and the generation of ultrasonic waves is stopped. Although FIGS. 2 and 3 show a case where one detection rod 32 is provided, a plurality of detection rods 32 may be provided.

FIG. 4 is a block diagram showing a controller 50 as control means. The controller 50 includes a control circuit 51 for driving an electromagnetic valve, an ultrasonic wave generation circuit 52, and a spray detection circuit 53. The solenoid valve drive control circuit 51 includes:
A signal from a speed detector 47 is sent to the control panel 21 via a conductor S, and the signal is compared with a memory 27 for determining printing conditions and stored in the memory 27. Based on the data on the relationship between the printing speed and the amount of water, the control panel 21 controls the opening / closing ratio of the solenoid valves 33a to 33d, the opening / closing frequency within a predetermined time, and the solenoid valves 33a, 33a.
A signal for shifting the opening / closing timing of 3b, 33c, 33d is issued. This signal is transmitted to each of the electromagnet sections 34a to 34a by the power distribution circuit 22.
34d via the conductors E, F, G, H, and the solenoid valve 33
a to 33d are opened and closed.

The ultrasonic wave generating circuit 52 includes the ultrasonic wave control panel 23
And the power distribution circuit 24. The spray detection circuit 53 includes the detection circuit 25 and the power distribution circuit 26. Detection rods 32a to 32
When the presence of the dampening solution is detected by d, a signal confirming the presence of the dampening solution is sent to the power distribution circuit 2 via the conductors M, N, O, and P.
Enter 6. Under this condition, no current is sent from the power distribution circuit 24 of the ultrasonic wave generating circuit 52 to the ultrasonic oscillator 39, and no ultrasonic wave is generated.

On the other hand, if, for example, the dampening solution is not detected by the detecting rod 32a even though the dampening solution is present in the nozzle 31a, a signal confirming the presence of the dampening solution is sent to the conductor M.
It does not enter the power distribution circuit 26 via M '. As a result, the detection circuit 25 detects that the hole 36a of the spray nozzle 31a is clogged, transmits this to the ultrasonic control panel 23, and connects the conducting wire A of the power distribution circuit 24 of the ultrasonic generation circuit 52 to a power supply. Thereby, the ultrasonic oscillator 39 of the spray device 30a is
a generates an ultrasonic wave. The ultrasonic oscillator 39a generates an ultrasonic wave only when there is a dampening solution pressurized in the nozzle 31a, and when the electromagnetic valve 33a is closed and there is no dampening solution pressurized in the nozzle 31a, Even if the hole 36a is clogged, no ultrasonic wave is generated. When pressurized dampening water is present in the nozzle 31a, ultrasonic waves act on the foreign matter clogged in the hole 36a, and the foreign matter is efficiently removed.

The controller 50 as an example of the control means is described above.
However, the present invention is not limited to this controller 50. When the spray detecting means detects that the dampening solution is not normally sprayed from the nozzle, the ultrasonic oscillator moves toward the nozzle hole. Any control means may be used as long as it generates ultrasonic waves and cleans the clogged nozzle holes with ultrasonic waves. In this embodiment, the one-fluid system in which the pressurized dampening solution is sprayed from the spray nozzle through the electromagnetic valve has been described. However, the two-fluid system in which the dampening solution is mixed with the compressed air and sprayed from the spray nozzle. This may be used for a spray nozzle of the type.

[0026]

As described above, according to the present invention, the spray state of the spray dampening solution supply device for an offset printing press is always detected, and the spray nozzle hole becomes clogged with foreign matter, and the spray state becomes abnormal. For example, the holes can be cleaned with ultrasonic waves to remove foreign matter, and a defective supply of dampening solution can be reliably prevented, so that printing quality can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an offset printing press 1 having a spray dampening water supply device.

FIG. 2 is a system diagram showing an overall configuration of the spraying dampening solution supply device for offset according to one embodiment of the present invention.

FIG. 3 is a sectional view of the spraying device 30 used in the present invention.

FIG. 4 is a block diagram of a controller 50.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Offset printing machine 30 Spray device 31 Spray nozzle 32 Detecting rod 33 Electromagnetic valve 34 Electromagnet part 35 Spray nozzle main body 36 Hole 37 Vibration-proof material 38 Water passage 39 Ultrasonic oscillator 40 Printing plate 41 Cylinder 50 Controller 51 Electromagnetic valve drive Control circuit 52 Ultrasonic wave generation circuit 53 Spray detection circuit

Claims (1)

(57) [Scope of request for utility model registration] 1. A spray dampening solution supply device for an offset printing press, comprising: an ultrasonic oscillator for cleaning a hole of each nozzle in each spray nozzle; and a circumference of a predetermined spray angle on a dampening solution spray side. A detecting means for detecting the dampening solution sprayed thereon; and a control means for driving the ultrasonic oscillator, wherein a solenoid valve drive control circuit or a metering pump device of the spray dampening water supply device for the offset printing press is provided. When the signal from the motor drive control circuit is a signal for supplying dampening water and the signal from the detecting means is a signal that does not detect the spray of dampening water, the control means A spray dampening water supply device for an offset printing press, characterized by driving an oscillator.