Dot marking and printing system and method of use thereof

Abstract

This invention provides a dot-shaped marking and printing system and a method for using the same that can prevent nozzle clogging of the discharge nozzle. [Solution] The dot marking and printing system 60 comprises a dot marking and printing device 1 equipped with a paint chamber 2, a discharge control valve 22, a discharge nozzle 11, a cleaning agent passage 3, and a cleaning agent flow path 30, and a compressed air pipe 80 capable of supplying compressed air, a cleaning air solenoid valve 73, a paint pipe 81 for pressurizing the paint, a paint supply stop solenoid valve 71, a cleaning agent pipe 84 for pressurizing the cleaning agent 5, a cleaning solenoid valve 74, a pressure reducing device 62, and a pressure reducing device pipe 83. After filling the cleaning agent passage 3 and the cleaning agent flow path 30 with cleaning agent 5, the pressure reducing device 62 is activated to reduce the pressure inside the paint chamber 2 of the dot marking and printing device 1, and the discharge control valve 22 is opened 1 to 10 times to draw in and maintain the cleaning agent 5 in the paint flow path 32, which is inside the discharge nozzle 11.

Description

Technical Field

[0001] The present invention relates to a dot marking and printing device for dot printing on products such as steel materials.

Background Art

[0002] Conventionally, dot marking and printing devices used in this type of dot marking and printing system have a discharge nozzle suitable for dot printing at their tips, and a discharge control valve composed of a valve seat and a spherical valve body is formed inside the discharge nozzle. This spherical valve body is integrally connected to the movable iron core of a vibration mechanism, for example, an electromagnetic solenoid, via a rod. A paint chamber filled with pressurized paint is provided around the valve seat and the spherical valve body. The discharge control valve opens and closes due to the reciprocating motion of the movable iron core, and dot-shaped liquid paint is intermittently discharged from the discharge nozzle. When the paint is left standing, it solidifies due to drying and the nozzle becomes clogged. Therefore, conventionally, in order to prevent the paint in the discharge nozzle from solidifying, it was necessary to periodically clean the periphery of the discharge nozzle with a cleaning agent or to periodically perform a purge of the paint to counter the solidification of the paint in the nozzle. However, simply filling the periphery of the discharge nozzle with a cleaning agent could not prevent the paint in the discharge nozzle from solidifying, or periodic purging was required and the paint was wasted, or purging could not be performed at all when the power of the dot marking and printing device itself was turned off, and there was a problem that the solidification of the paint could not be prevented.

[0003] For example, in Patent Document 1, there is disclosed a method of using a dot marking and printing mechanism having a cleaning agent introduction step of filling a cleaning agent holding nozzle with the cleaning agent by flowing the cleaning agent into the cleaning agent holding nozzle, a cleaning agent discharge step of discharging the cleaning agent filled in the cleaning agent holding nozzle from a cleaning agent discharge port by flowing air into the cleaning agent holding nozzle once or a plurality of times, and a foam generation step of flowing a small flow rate of air into the cleaning agent holding nozzle. The technology described in Patent Document 1 is superior in that it can clean the spray surface by utilizing a small flow rate of air. However, the dot-shaped marking and printing mechanism and method of use disclosed in Patent Document 1 still have a problem in that it does not prevent the paint from solidifying inside the discharge nozzle.

[0004] Therefore, methods to easily prevent the paint from solidifying inside the discharge nozzle, and methods that eliminate the need for periodic blow-by spraying to prevent the paint from solidifying inside the discharge nozzle, were being considered. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2024-83067 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The present invention has been made with these points in mind, and provides a dot marking and printing device and a cleaning method thereof that does not require periodic paint blowing and prevents nozzle clogging by preventing the paint in the discharge nozzle from solidifying. [Means for solving the problem]

[0007] Therefore, the dot marking and printing system of the present invention comprises a dot marking and printing device equipped with a discharge nozzle for discharging paint, a paint chamber, a cleaning agent passage, and a cleaning agent flow path, wherein the paint chamber is equipped with a discharge control valve consisting of a valve seat and a valve body, and the dot marking and printing system further comprises a pressure reducing device and pressure reducing device piping, wherein the paint chamber of the dot marking and printing device and the pressure reducing device are connected at least by the pressure reducing device piping, and the pressure reducing device is capable of reducing the pressure applied to the paint in the paint chamber to atmospheric pressure or less.

[0008] Furthermore, the present invention includes a dot marking and printing device comprising a discharge nozzle for discharging paint, a paint chamber, a cleaning agent passage, and a cleaning agent flow path, wherein the paint chamber is equipped with a discharge control valve consisting of a valve seat and a valve body; a compressed air supply source; compressed air piping connecting the compressed air supply source and the dot marking and printing device; a cleaning air solenoid valve provided in the compressed air piping; a pressure reducing device; pressure reducing device piping connecting the pressure reducing device and the dot marking and printing device; and paint circulation piping connecting the dot marking and printing device and a paint tank for circulating the paint. The invention is characterized by comprising: a circulation solenoid valve provided in the material circulation piping; the paint tank; paint piping connecting the paint tank and the dot marking and printing device for supplying the paint to the dot marking and printing device; a paint pump for pressurizing the paint in the paint piping; a paint supply stop solenoid valve provided in the paint piping; a cleaning agent supply source; cleaning agent piping connecting the cleaning agent supply source and the dot marking and printing device for supplying the cleaning agent to the dot marking and printing device; and a cleaning solenoid valve provided in the cleaning agent piping.

[0009] Furthermore, the present invention relates to a method for using the dot marking and printing system according to claim 2, comprising a cleaning agent supply step for supplying the cleaning agent to the dot marking and printing device, and a depressurization step for depressurizing the paint chamber, wherein the cleaning agent supply step and the depressurization step are performed sequentially, the cleaning agent supply step is a step of opening the cleaning solenoid valve, closing the cleaning air solenoid valve, opening the circulation solenoid valve, and closing the paint supply stop solenoid valve, and the depressurization step is a step of simultaneously performing a step of opening the discharge control valve for a certain period of time, closing the cleaning solenoid valve, the cleaning air solenoid valve, the circulation solenoid valve, and the paint supply stop solenoid valve, and operating the depressurization device to depressurize the paint in the paint chamber to a pressure lower than atmospheric pressure.

[0010] The method of using the dot marking and printing system of the present invention further comprises a compressed air introduction step, the compressed air introduction step being a step of opening the cleaning air solenoid valve and closing the cleaning solenoid valve, the circulation solenoid valve and the paint supply stop solenoid valve, and the method of using the dot marking and printing system is characterized in that the cleaning agent supply step, the compressed air introduction step and the depressurization step are carried out in order.

[0011] Furthermore, the method of using the dot marking and printing system of the present invention is characterized in that the depressurization step comprises, instead of a step of keeping the discharge control valve open for a certain period of time, a step of opening the discharge control valve and immediately closing it 1 to 10 times.

[0012] Furthermore, the method of using the dot marking and printing system of the present invention comprises a dot marking and printing device equipped with a discharge nozzle for discharging paint, a paint chamber, a cleaning agent passage, and a cleaning agent flow path, wherein the paint chamber is equipped with a discharge control valve consisting of a valve seat and a valve body; a compressed air supply source; compressed air piping connecting the compressed air supply source and the dot marking and printing device; a cleaning air solenoid valve provided in the compressed air piping; a pressure reducing device; pressure reducing device piping connecting the pressure reducing device and the dot marking and printing device; a paint tank; paint piping connecting the paint tank and the dot marking and printing device to supply the paint to the dot marking and printing device; a paint pump for pressurizing the paint in the paint piping; a paint supply stop solenoid valve provided in the paint piping; a cleaning agent supply source; cleaning agent piping connecting the cleaning agent supply source and the dot marking and printing device to supply the cleaning agent to the dot marking and printing device; and a cleaning device provided in the cleaning agent piping. A method for using a dot marking and printing system equipped with a solenoid valve, wherein the paint is ink, and the method for using the dot marking and printing system comprises a pressure return step for returning the pressure in the paint chamber to near atmospheric pressure, a second cleaning agent supply step for introducing the cleaning agent, and a second depressurization step, wherein the pressure return step, the second cleaning agent supply step, and the second depressurization step are performed sequentially, and the pressure return step involves turning the discharge control valve once ~ The process of opening the valve 10 times, closing the cleaning solenoid valve, closing the cleaning air solenoid valve, and closing the paint supply stop solenoid valve is performed simultaneously. The second cleaning agent supply process is a process of opening the cleaning solenoid valve and closing the cleaning air solenoid valve and the paint supply stop solenoid valve. The second depressurization process is a process of closing the cleaning solenoid valve, the cleaning air solenoid valve, and the paint supply stop solenoid valve, and operating the depressurization device to reduce the pressure in the paint chamber to a pressure lower than atmospheric pressure. [Effects of the Invention]

[0013] The present invention relates to a dot marking and printing system comprising a dot marking and printing device equipped with a discharge nozzle for discharging paint, a paint chamber, a cleaning agent passage, and a cleaning agent flow path, wherein the paint chamber is equipped with a discharge control valve consisting of a valve seat and a valve body, and the dot marking and printing system further comprises a pressure reducing device and pressure reducing device piping, wherein the paint chamber of the dot marking and printing device and the pressure reducing device are connected by at least pressure reducing device piping, and the pressure reducing device is capable of reducing the pressure on the paint in the paint chamber to below atmospheric pressure, so that the cleaning agent can be drawn into the discharge nozzle by reducing the pressure in the paint chamber, thereby eliminating the need for periodic paint blowing and preventing the paint in the discharge nozzle from solidifying, thus preventing nozzle clogging.

[0014] Furthermore, the present invention provides a dot marking and printing device comprising a discharge nozzle for discharging paint, a paint chamber, a cleaning agent passage, and a cleaning agent flow path, wherein the paint chamber is equipped with a discharge control valve consisting of a valve seat and a valve body; a compressed air supply source; compressed air piping connecting the compressed air supply source and the dot marking and printing device; a cleaning air solenoid valve provided in the compressed air piping; a pressure reducing device; pressure reducing device piping connecting the pressure reducing device and the dot marking and printing device; paint circulation piping connecting the dot marking and printing device and a paint tank for circulating paint; a circulation solenoid valve provided in the paint circulation piping; a paint tank; and a device for supplying paint to the dot marking and printing device. The system is characterized by comprising paint piping connecting a paint tank and a dot marking and printing device, a paint pump for pressurizing paint through the paint piping, a paint supply stop solenoid valve provided in the paint piping, a cleaning agent supply source, cleaning agent piping connecting the cleaning agent supply source and the dot marking and printing device to supply the cleaning agent to the device, and a cleaning solenoid valve provided in the cleaning agent piping. As such, it is possible to draw the cleaning agent into the discharge nozzle by reducing the pressure in the paint chamber, thereby eliminating the need for periodic paint blowing and preventing the paint in the discharge nozzle from solidifying, thus preventing nozzle clogging.

[0015] Furthermore, the present invention relates to a method for using the dot marking and printing system according to claim 2, comprising a cleaning agent supply step for supplying a cleaning agent to a dot marking and printing device, and a depressurization step for depressurizing the paint chamber, wherein the cleaning agent supply step and the depressurization step are performed sequentially, the cleaning agent supply step is a step of opening the cleaning solenoid valve, closing the cleaning air solenoid valve, opening the circulation solenoid valve, and closing the paint supply stop solenoid valve, and the depressurization step is a step of simultaneously performing a step of opening the discharge control valve for a certain period of time, closing the cleaning solenoid valve, cleaning air solenoid valve, circulation solenoid valve, and paint supply stop solenoid valve, and operating a depressurization device to depressurize the paint in the paint chamber to a pressure lower than atmospheric pressure. As a result, by depressurizing the paint chamber, it is possible to draw the cleaning agent into the discharge nozzle, thereby eliminating the need for periodic paint blowing and preventing the paint in the discharge nozzle from solidifying, thus preventing nozzle clogging.

[0016] Furthermore, the method of using the dot marking and printing system of the present invention further includes a compressed air introduction step, the compressed air introduction step being a step of opening the cleaning air solenoid valve and closing the cleaning solenoid valve, the circulation solenoid valve and the paint supply stop solenoid valve, and the method of using the dot marking and printing system is characterized in that the cleaning agent supply step, the compressed air introduction step and the depressurization step are carried out in order, so that air can be drawn into the discharge nozzle by depressurizing the paint chamber, thereby eliminating the need for periodic paint blowing and preventing the paint in the discharge nozzle from solidifying, thus preventing nozzle clogging.

[0017] Furthermore, in the method of using the dot marking and printing system of the present invention, the depressurization step is characterized by comprising a step of opening the discharge control valve and immediately closing it 1 to 10 times, instead of a step of keeping the discharge control valve open for a certain period of time. Therefore, by depressurizing the paint chamber, it is possible to draw air or cleaning agent into the discharge nozzle, and it is possible to control the amount of air or cleaning agent drawn in.

[0018] Furthermore, the method of using the dot marking and printing system of the present invention is a dot marking and printing system using a dot marking and printing system comprising: a dot marking and printing device equipped with a discharge nozzle for discharging paint, a paint chamber, a cleaning agent passage, and a cleaning agent flow path, wherein the paint chamber is equipped with a discharge control valve consisting of a valve seat and a valve body; a compressed air supply source; compressed air piping connecting the compressed air supply source and the dot marking and printing device; a cleaning air solenoid valve provided in the compressed air piping; a pressure reducing device; pressure reducing device piping connecting the pressure reducing device and the dot marking and printing device; a paint tank; paint piping connecting the paint tank and the dot marking and printing device to supply paint to the dot marking and printing device; a paint pump for pressurizing the paint in the paint piping; a paint supply stop solenoid valve provided in the paint piping; a cleaning agent supply source; cleaning agent piping connecting the cleaning agent supply source and the dot marking and printing device to supply cleaning agent to the dot marking and printing device; and a cleaning solenoid valve provided in the cleaning agent piping. The method of use of the dot marking and printing system, wherein the paint is ink, comprises a pressure return step to return the pressure in the paint chamber to near atmospheric pressure, a second cleaning agent supply step to introduce a cleaning agent, and a second depressurization step, wherein the pressure return step, the second cleaning agent supply step, and the second depressurization step are performed sequentially, the pressure return step simultaneously involves opening the discharge control valve 1 to 10 times, closing the cleaning solenoid valve, closing the cleaning air solenoid valve, and closing the paint supply stop solenoid valve, and the second cleaning agent supply step is, The first step involves opening the cleaning solenoid valve and closing the cleaning air solenoid valve and the paint supply stop solenoid valve. The second depressurization step involves closing the cleaning solenoid valve, the cleaning air solenoid valve, and the paint supply stop solenoid valve, and activating the depressurization device to reduce the pressure in the paint chamber to a level lower than atmospheric pressure. By reducing the pressure in the paint chamber, it is possible to draw the cleaning agent into the discharge nozzle, thus eliminating the need for periodic paint blowing and preventing the paint in the discharge nozzle from solidifying, thereby preventing nozzle clogging. [Brief explanation of the drawing]

[0019] [Figure 1]It is a schematic cross-sectional view showing an example of the dot marking and printing device 1 according to this embodiment. [Figure 2] It is an explanatory view in which a cross-section is cut out so as to expose the inside of the nozzle plate 10 and the discharge nozzle 11 provided in the dot marking and printing device 1 of the present invention. [Figure 3] It is a diagram showing the piping of the dot marking and printing system 60 according to this embodiment. [Figure 4] It is a process diagram showing a usage method 90 of the dot marking and printing system 60 according to this embodiment. [Figure 5] It is a diagram showing the internal state of the dot marking and printing device 1 when the usage method 90 etc. of the dot marking and printing system according to this embodiment are carried out. (X) shows the state after the printing process, (Y) shows the state after the cleaning agent supply process 91 is carried out in the usage method 90, and (Z) shows the state when the decompression process 92 is being carried out in the usage method 90, respectively, which are explanatory views. [Figure 6] It is a diagram showing the internal state of the dot marking and printing device 1 when the usage method 90 etc. of the dot marking and printing system according to this embodiment are carried out. (X) is a diagram showing the state when the discharge control valve 22 is in the closed state during the decompression process 92 in the usage method 90, (Y) is a diagram showing the state when the air process 93 is carried out in the usage method 90, and (Z) is an explanatory view showing the state after the blowing-off process 94 is carried out in the usage method 90. [Figure 7] It is a process diagram showing another example of the usage method of the dot marking and printing system 60 according to this embodiment, which is a usage method 100. [Figure 8] It is a diagram showing the internal state of the dot marking and printing device 1 when the usage method 100 of the dot marking and printing system according to this embodiment is carried out. (X) is an explanatory view showing the state after the compressed air introduction process 95 of the usage method 100 is carried out, and (Y) is an explanatory view showing the state after the decompression process 92 of the usage method 100 is carried out. [Figure 9]It is a process diagram showing another example of the usage method 110 of the dot-shaped marking and printing system 60 according to this embodiment.

Mode for Carrying Out the Invention

[0020] The following describes the details of embodiments of the present invention with reference to the drawings. First, drawings showing the dot marking and printing device 1 and the dot marking and printing system 60 and their usage methods according to this embodiment will be described. Figure 1 is a schematic cross-sectional view showing an example of the dot marking and printing device 1 according to this embodiment. Figure 2 is an explanatory diagram showing a cross-section of the nozzle plate 10 and discharge nozzle 11 of the dot marking and printing device 1 of the present invention, with the interior exposed. Figure 3 is a piping diagram showing the piping of the dot marking and printing system 60 according to this embodiment. The dashed lines indicate the piping routes through which compressed air passes, the solid lines indicate the piping routes through which paint 6 passes, and the dashed lines indicate the piping routes through which cleaning agent 5 passes. The P mark indicates a pump, and the opposing triangular marks indicate solenoid valves. The black circles indicate piping branching points. Figure 4 is a process diagram showing the usage method 90 of the dot marking and printing system 60 according to this embodiment. Figure 5 is a diagram showing the internal state of the dot marking and printing device 1 when the usage method 90 of the dot marking and printing system 60 according to this embodiment is performed, where (X) is the state after the printing process, (Y) is the state after the cleaning agent supply process 91 in usage method 90, and (Z) is the state when the depressurization process 92 is performed in usage method 90. Figure 6 is a diagram showing the internal state of the dot marking and printing device 1 when the usage method 90 of the dot marking and printing system 60 according to this embodiment is performed, where (X) is the state when the discharge control valve 22 is closed during the depressurization process 92 in usage method 90, (Y) is the state when the air process 93 is performed in usage method 90, and (Z) is the state after the blow-off process 94 is performed in usage method 90. Figure 7 is a process diagram showing usage method 100, which is another example of the usage method of the dot marking and printing system 60 according to this embodiment.Figure 8 is a diagram showing the internal state of the dot marking and printing device 1 when the usage method 100 of the dot marking and printing system 60 according to this embodiment is performed, where (X) is a diagram showing the state after the compressed air introduction step 95 of usage method 100 is performed, and (Y) is an explanatory diagram showing the state after the depressurization step 92 of usage method 100 is performed. Figure 9 is a process diagram showing usage method 110, which is another example of the usage method of the dot marking and printing system 60 according to this embodiment. In the process diagrams of Figures 4, 7, and 9, each step and its sequence are shown at the top, and below that, a time chart showing the details of each step is illustrated. Two dotted lines are drawn parallel to the right of the name of each solenoid valve, with the upper of the two dotted lines indicating the open state and the lower of the two dotted lines indicating the closed state. When a solid line is drawn on the upper line, it indicates that the valve is in the open state, and when it is drawn on the lower line, it indicates that the valve is in the closed state. Furthermore, in Figures 5, 6, and 8, the diagonal lines indicate areas filled with paint 6, and the grid-like diagonal lines indicate areas filled with cleaning agent 5. For the purposes of this disclosure, "upper side" refers to the right side in Figure 1 and the upward direction in Figures 5, 6, and 8, while "lower side" refers to the opposite side. Left and right will also be explained as appropriate based on these reference points.

[0021] The dot marking and printing device 1 shown in Figure 1 consists of a paint chamber 2, a cleaning agent passage 3, a nozzle plate 10, a wall separating the cleaning agent passage 3 from the paint chamber 2, and a discharge nozzle 11. First, the paint chamber 2 is provided to pressurize paint 6 to the discharge nozzle 11 and is equipped with a discharge control valve 22 to control the pressurization. As shown in Figure 1, the discharge control valve 22 consists of a valve body 21 and a valve seat 20, and controls the interval at which paint 6 is pressurized to the discharge nozzle 11 sandwiched between the valve seat 20 by operating so that the valve body 21 is pressed against the valve seat 20 or has a gap. The valve body 21 is connected to a rod-shaped movable iron core 23 shown in Figure 1, and the other end of the movable iron core 23 is connected to a vibration mechanism 24, which controls the operation so that the valve body 21 is pressed against the valve seat 20 or has a gap. As a result, pressurized paint 6 is discharged from the discharge nozzle 11.

[0022] In this disclosure, "paint 6" refers to a liquid paint 6 that includes paint or ink and is capable of marking and printing.

[0023] Next, the detergent passage 3 and the detergent flow path 30 will be described in detail. The detergent passage 3 is a passage for introducing the detergent 5 into the nozzle plate 10 from a detergent supply source 64, which is composed of a tank or the like (not shown in Figure 1). In addition, when the detergent 5 is discharged, air for discharging the detergent 5 is introduced into the detergent passage 3 via a separate route. For this reason, the detergent passage 3 is equipped with a detergent inlet for introducing the detergent 5 into the nozzle plate 10 and a compressed air inlet for introducing air for discharging the detergent 5 into the detergent passage 3 (not shown). The cleaning agent passage 3 is connected to a cleaning agent flow path 30, which is provided in the same number as the discharge nozzles 11, and the cleaning agent 5 flows from the cleaning agent passage 3 to the cleaning agent flow path 30. Furthermore, since the cleaning agent passage 3 is constructed by fitting the nozzle plate 10 and forming the passage in the gap between them, it is necessary to prevent the cleaning agent 5 from leaking outside the dot marking and printing device 1. Therefore, a sheet 25 that functions as a packing is attached so as to be in close contact with the wall of the cleaning agent passage 3 on the paint chamber 2 side. The sheet 25 acts as a packing to prevent the cleaning agent 5 from leaking out. For this reason, it is sufficient to provide it on the outside of the cleaning agent passage 3, surrounding it. In Figure 1, a flow path is provided in the cleaning agent passage 3 that bypasses the sheet 25 and connects to an air compressor and a cleaning agent pump (not shown). Furthermore, the dot marking and printing device 1 of the present invention is not limited to a configuration comprising a nozzle plate 10, and the paint chamber 2, cleaning agent passage 3 and cleaning agent flow path 30, a wall separating the cleaning agent passage 3 and the paint chamber 2, wall portion 31, etc., may be integrally configured.

[0024] The detergent flow path 30 is surrounded by the detergent holding nozzle 12 and surrounds the discharge nozzle 11. A cylindrical shape is preferred for the detergent flow path 30 in order to reduce flow resistance. However, an atomizing section may be provided near the detergent outlet 52 of the detergent flow path 30, which has a narrower flow path cross-section than the rest of the flow path and is provided for atomization.

[0025] Next, we will describe the wall portion 31, which is a wall separating the two detergent flow paths 30. The wall portion 31 is not provided for each detergent flow path 30, but is integrally formed on the nozzle plate 10 as a single wall that separates the two detergent flow paths 30. As a result, the width of the pitch Z between the discharge nozzles 11 can be significantly reduced compared to conventional designs.

[0026] Next, the nozzle plate 10 will be further explained using Figure 1. The cleaning agent passage 3 is formed between the nozzle plate 10 and the wall between the cleaning agent passage 3 and the paint chamber 2, surrounded by a sheet 25. The cleaning agent passage 3 continues to the next cleaning agent passage 30 while the cleaning agent 5 flows through the cleaning agent passage 30, and multiple cleaning agent passages 30 and corresponding discharge nozzles 11 can be provided for each cleaning agent passage 3. In the example shown in Figure 1, two discharge nozzles 11 and two cleaning agent passages 30 are shown, but this is not limited to this, and it is possible to increase or decrease the number of nozzles to three or four, or two or three rows, as long as it is feasible from a design perspective. In this case, the cleaning agent passage 3 is designed as appropriate.

[0027] As shown in Figure 1, the detergent holding nozzle 12 is further equipped with a detergent discharge port 52. The detergent 5, introduced from the detergent passage 3 and having passed through each detergent flow path 30, is pushed out by compressed air supplied from a compressed air inlet (not shown) of the detergent passage 3. As a result, the detergent 5 is discharged from the detergent discharge port 52 located at the end of the detergent flow path 30 opposite to the side communicating with the detergent passage 3.

[0028] Next, the cleaning agent holding nozzle 12, cleaning agent passage 3, and cleaning agent flow path 30 of the dot marking and printing device 1 will be described in detail when used for dot marking and printing. First, atomization is performed in the cleaning agent flow path 30. Atomization is the part in which the paint 6 is atomized by the discharge nozzle 11 and compressed air. For this reason, atomization is performed using compressed air introduced from the cleaning agent passage 3 and passing through the cleaning agent flow path 30. For this reason, an atomizing section may be provided near the tip of the discharge nozzle 11, in which the flow path cross-section is narrower than that of other parts of the cleaning agent flow path 30. It is preferable that the atomizing section has a narrower cross-sectional area than other parts of the cleaning agent flow path 30, so that the compressed air is accelerated in the atomizing section, and when the paint 6 is discharged from the discharge nozzle 11, the droplets of paint 6 can be atomized with less compressed air.

[0029] Next, we will discuss the wall portion 31, which is a wall separating the two detergent flow paths 30. Conventionally, the wall portion 31 was provided on both sides of each detergent flow path 30, but this configuration resulted in two wall portions 31 being provided between adjacent detergent flow paths 30, creating wasted space. By providing the wall portion 31 as a single wall separating the two detergent flow paths 30 on the nozzle plate 10, as in the nozzle plate 10, the width of the pitch Z between the discharge nozzles 11 can be significantly reduced compared to conventional designs.

[0030] The nozzle plate 10 will be described in more detail. The detergent passage 3 has a compressed air inlet, which is a hole for introducing air from a compressed air supply source 61, which is composed of an air compressor or the like (not shown), from the outside. As shown in Figure 1, the detergent passage 3 is in communication with a plurality of detergent passages 30.

[0031] This configuration, in which the detergent passage 3 communicates with the detergent flow path 30, allows compressed air and detergent 5 to be supplied to multiple detergent flow paths 30 simultaneously from a single compressed air supply source 61.

[0032] Next, the discharge nozzle 11 will be described in detail with reference to Figure 2. Figure 2 shows that the discharge nozzle 11 comprises a discharge port 51 and a paint flow path 32. In this embodiment, the volume of the paint flow path 32 is 0.1 to 1 microliter per discharge nozzle 11, and when 16 discharge nozzles 11 are provided, the total volume is a very small amount of 1.6 to 16 microliters. However, this is an example and is not limited to this volume. Paint 6 is supplied from the paint chamber 2 shown in Figure 1 to the paint flow path 32 of the discharge nozzle 11 when the valve body 21 separates from the valve seat 20 in the discharge control valve 22. The paint 6 is discharged from the discharge port 51 through the paint flow path 32 and atomized at the end of the cleaning agent flow path 30, thereby performing dot marking and printing.

[0033] Next, a cleaning method for the conventional dot marking and printing device 1 will be described. First, the cleaning agent 5 is introduced into the cleaning agent holding nozzle 12 using the cleaning agent passage 3. Then, the inside of the cleaning agent holding nozzle is filled with the cleaning agent 5. At this time, it is also preferable to maintain the state of being filled with the cleaning agent 5 for 1 to 3 seconds. Finally, the cleaning agent 5 inside the cleaning agent holding nozzle 12 is discharged from the cleaning agent discharge port 52 using compressed air or other air.

[0034] Next, the configuration of the dot marking and printing system 60, which is suitable for implementing the methods 90 and 100 for using the dot marking and printing system 60 for cleaning the dot marking and printing device 1 according to the present invention, will be described in detail. Figure 3 is a piping diagram showing the piping for compressed air, paint 6, and cleaning agent 5. First, the piping route of the compressed air will be explained. The compressed air piping 80 connected to the compressed air supply source 61 branches into piping connected to the pressure reducing device 62 and piping connected to the dot marking and printing device 1. In the compressed air piping 80, a cleaning air solenoid valve 73 is provided between the branching point and the connection to the dot marking and printing device 1. When the compressed air piping 80 is connected to the dot marking and printing device 1, it is connected to a compressed air inlet (not shown) of the cleaning agent passage 3 shown in Figure 1.

[0035] Next, the piping route for the paint 6 of the dot marking and printing system 60 will be described. The piping route for the paint 6 consists of paint piping 81, paint circulation piping 82 provided for the circulation of paint 6, and pressure reducing device piping 83 for connecting to the pressure reducing device 62. First, the paint piping 81 will be described in detail. Paint piping 81 is connected to a paint tank 63 which has the function of storing paint 6. Starting from the paint tank 63, paint piping 81 first connects to a paint pump 65, and starting from the paint pump 65, it further connects to the dot marking and printing device 1. Paint piping 81 is further equipped with a paint supply stop solenoid valve 71 in the route between the paint pump 65 and the dot marking and printing device 1. The paint pump 65 has the function of pressurizing and pumping paint 6 within the paint piping 81.

[0036] Next, the routes of the paint circulation piping 82 and the pressure reducing device piping 83 will be described. The paint circulation piping 82 is a pipe provided to circulate the paint 6 in order to prevent the components of the paint 6 from separating and settling due to the stagnation of the paint 6. The paint circulation piping 82 is connected to the paint chamber 2 of the dot marking and printing device 1. Starting from the dot marking and printing device 1, the paint circulation piping 82 first branches into a route that connects to the paint tank 63 and a pressure reducing device piping 83 that connects to the pressure reducing device 62. Alternatively, the pressure reducing device piping 83 may be configured to connect directly to the paint chamber 2 of the dot marking and printing device 1 without this branching configuration. After branching, the paint circulation piping 82 connects to the paint tank 63. The paint circulation piping 82 is equipped with a circulating solenoid valve 72 in the route between the point where it branches and the point where it reaches the paint tank 63. The paint tank 63 only needs to be able to store the paint 6, and can be a tank or other known configuration.

[0037] The circulation of paint 6 in the paint circulation piping 82 will be further explained with reference to Figure 3. When paint 6 is being pumped through the paint piping 81 by the paint pump 65, if the circulation solenoid valve 72 is open, paint 6 will flow through the paint circulation piping 82 toward the paint tank 63. When the paint supply stop solenoid valve 71 is closed, the pumping of paint 6 from the paint tank 63 toward the paint chamber 2 of the dot marking and printing device 1 is stopped. In this case, if the circulation solenoid valve 72 is opened, the pressure on the paint 6 inside the paint chamber 2 is released and the pressure is reduced to near atmospheric pressure.

[0038] The pressure reducing device 62 is connected to the paint chamber 2 of the dot marking and printing device 1 via pressure reducing device piping 83. In the dot marking and printing system 60 of this embodiment, the pressure reducing device 62 is composed of a cylinder with a pressure reducing chamber and a switching valve, but the pressure reducing device 62 is not limited to this, and may be of a diaphragm type, vacuum pump type, or aspirator type in addition to the cylinder type. The pressure reducing device 62 only needs to have the function of reducing the pressure on the paint 6 in the paint chamber 2 to below atmospheric pressure.

[0039] Next, the supply route for the cleaning agent 5 will be described. The supply route for the cleaning agent 5 begins with the cleaning agent piping 84 connecting to the cleaning agent supply source 64. The cleaning agent supply source 64 only needs to be able to store the cleaning agent 5 and can be a known configuration such as a tank. The cleaning agent piping 84 starts from the cleaning agent supply source 64 and connects to the cleaning agent pump 66. After the cleaning agent pump 66, it connects to a cleaning agent inlet (not shown) in the cleaning agent passage 3 of the dot marking and printing device 1. This allows the cleaning agent 5 to flow into the cleaning agent passage 3. Between the cleaning agent pump 66 and the connection to the dot marking and printing device 1, the cleaning agent piping 84 is further equipped with a cleaning solenoid valve 74. By closing the cleaning solenoid valve 74, the supply of cleaning agent 5 from the cleaning agent piping 84, which is in the liquid supply state, to the dot marking and printing device 1 can be stopped.

[0040] Here, with reference to Figures 1 and 3, the process by which the cleaning agent 5 is introduced into the cleaning agent passage 3 via the cleaning agent inlet will be described in detail. When the cleaning solenoid valve 74 is open, the cleaning agent 5 is pumped to the cleaning agent inlet, filling the cleaning agent passage 3 and the cleaning agent flow path 30 with the cleaning agent 5. The cleaning agent pressure at this time is, for example, 0.1 to 0.3 megapascals. In this embodiment, the amount of cleaning agent 5 used to fill the cleaning agent passage 3 and the cleaning agent flow path 30 is, for example, about 0.1 to 1 milliliter per use.

[0041] By filling the detergent-holding nozzle 12 with the detergent 5, the discharge nozzle 11 and its tip will remain inside the detergent outlet 52, which is below it, due to surface tension. This allows for cleaning and cooling by removing excess heat. However, if the discharge port 51 protrudes significantly beyond the detergent outlet 52, it becomes difficult to immerse the tip of the discharge nozzle 11 in the detergent 5. Therefore, it is preferable that the discharge port 51 be located near or inside the detergent outlet 52.

[0042] The paint supply stop solenoid valve 71, circulation solenoid valve 72, cleaning air solenoid valve 73, and cleaning solenoid valve 74 shown in Figure 3 are preferably composed of solenoid valves whose valve bodies 21 are opened and closed by controlling the current supplied to the electromagnets (solenoids), but are not limited to this, and other existing configurations may be used.

[0043] Next, methods 90, 100, and 110 for using the dot marking and printing system 60 to clean the dot marking and printing device 1 of the present invention will be described.

[0044] First, we will explain the state before methods 90, 100, and 110 are implemented. Figure 5 illustrates the dot marking and the inside of the printing device 1 when method 90 is implemented. Figure 5(X) shows the state before methods 90, 100, and 110 according to this embodiment are implemented. In the printing process, the paint 6 filling the paint chamber 2 is pushed out into the paint flow path 32 in the discharge nozzle 11 by opening and closing the discharge control valve 22. As a result, droplets of paint 6 are discharged from the discharge port 51 by the discharge nozzle 11, and the droplets of paint 6 are atomized by compressed air in the cleaning agent flow path 30 and blown towards the object to be printed. Figure 5(X) shows the state after this printing process. After the printing process, as shown in Figure 5(X), the inside of the discharge nozzle 11 is filled with paint 6.

[0045] In conventional cleaning methods for dot marking and printing devices 1, paint 6 remains in the discharge nozzle 11 after the printing process, which can cause the paint 6 to harden due to drying, leading to nozzle clogging. Furthermore, to prevent this, it was necessary to periodically spray the paint 6 as a spit, resulting in wasted paint 6. In addition, the dot marking and printing device 1 had to be powered on to perform the spit, and if the power was turned off, the spit could not be performed at all, making it impossible to prevent nozzle clogging.

[0046] Therefore, as shown in Figure 4, in the method of use 90 of the dot marking and printing system 60 according to this embodiment, the cleaning agent supply step 91, the depressurization step 92, the air step 93, and the blow-out step 94 are performed sequentially after the printing step.

[0047] First, the cleaning agent supply process 91 will be described in detail with reference to Figure 4. In the cleaning agent supply process 91, the discharge control valve 22 is in the closed state. That is, the valve body 21 shown in Figure 1 is pressed against the valve seat 20, blocking the paint chamber 2 and the paint flow path 32 in the discharge nozzle 11. Also in the cleaning agent supply process 91, the cleaning solenoid valve 74 opens after the circulation solenoid valve 72 opens. When the cleaning solenoid valve 74 opens, the cleaning agent 5 is introduced into the cleaning agent passage 3 through the cleaning agent inlet. Then, the cleaning agent passage 3 and the cleaning agent flow path 30 are filled with the cleaning agent 5. Then, due to the surface tension phenomenon at the cleaning agent discharge port 52, the cleaning agent 5 is maintained in the cleaning agent holding nozzle 12. This is shown in Figure 5(Y). Also, in the cleaning agent supply process 91, the cleaning air solenoid valve 73 is in the closed state, and compressed air is not supplied to the cleaning agent passage 3. Furthermore, in the cleaning agent supply process 91, the circulation solenoid valve 72 is open, and the paint supply stop solenoid valve 71 is closed. As a result, the paint pressure on the paint 6 filling the paint chamber 2 drops to near atmospheric pressure. In the cleaning agent supply process 91, the pressure reducing device 62 does not operate to reduce the pressure in the paint chamber 2. The cleaning agent supply process 91 transitions from the state in Figure 5(X) to the state in Figure 5(Y). In the state in Figure 5(Y), after the cleaning agent supply process 91 has been performed, the discharge nozzle 11 remains filled with paint 6.

[0048] In the method of use 90 of the dot marking and printing system 60 of the present invention, as shown in Figure 4, a depressurization step 92 is provided after the cleaning agent supply step 91. In the depressurization step 92, as shown in Figure 4, the discharge control valve 22 is first opened for a certain period of time. Instead of the discharge control valve 22 being open for a certain period of time, the discharge control valve 22 may be opened and closed 1 to 10 times. In the depressurization step 92, the cleaning solenoid valve 74, the cleaning air solenoid valve 73, the circulation solenoid valve 72, and the paint supply stop solenoid valve 71 are closed. In the depressurization step 92, the depressurization device 62 is activated. As a result, the paint chamber 2 in Figure 5(Y) is depressurized to below atmospheric pressure, and the discharge control valve 22 is opened for a certain period of time, drawing the cleaning agent 5 into the discharge nozzle 11, and drawing the paint 6 into the paint chamber 2 which has been depressurized to below atmospheric pressure.

[0049] In the depressurization process 92, when the discharge control valve 22 is opened and closed 1 to 10 times, the amount of paint 6 drawn into the paint chamber 2 per opening is constant, and the amount of cleaning agent 5 filling the cleaning agent flow path 30 shown in Figure 5(Y) is drawn into the paint flow path 32 from the discharge port 51 of the discharge nozzle 11. Therefore, by appropriately designing the opening and closing of the discharge control valve 22 between 1 and 10 times, the total amount drawn in when the cleaning agent 5 is drawn into the paint flow path 32 of the discharge nozzle 11 can be controlled by appropriately designing the number of openings and closings. Therefore, by appropriately designing the number of openings and closings of the discharge control valve 22, it is possible to design a process that fills only the paint flow path 32 in the discharge nozzle 11 with cleaning agent 5, preventing the cleaning agent 5 from being drawn into the paint chamber 2. Therefore, it is possible to suppress the mixing of cleaning agent 5 into the paint chamber 2. The 1 to 10 opening and closing cycles of the discharge control valve 22 should have the same opening time as when the paint 6 is discharged from the discharge nozzle 11 during the printing process for dot marking and printing. By performing the depressurization process 92, the system transitions from the state shown in Figure 5(Y) to the state shown in Figure 5(Z). In Figure 5(Z), the discharge control valve 22 is in the open state, and the cleaning agent 5 that has filled the cleaning agent holding nozzle 12 also fills the paint flow path 32 in the discharge nozzle 11. Figure 6(X) shows the discharge control valve 22 closing after the state shown in Figure 5(Z).

[0050] The method of use 90 of the dot marking and printing system 60 according to this embodiment includes an air process 93, which is performed immediately before the printing process, after the depressurization process 92, as shown in Figure 4. As shown in Figure 4, in the air process 93, the discharge control valve 22, the cleaning solenoid valve 74, and the circulation solenoid valve 72 are in a closed state, while the cleaning air solenoid valve 73 and the paint supply stop solenoid valve 71 are in an open state. In the air process 93, the paint supply stop solenoid valve 71 may also be in a closed state. In addition, the depressurization device 62 is not operating in the air process 93.

[0051] By performing the air process 93, the cleaning air solenoid valve 73 is open, and compressed air is introduced into the cleaning agent passage 3 from the compressed air inlet, thus introducing compressed air into the cleaning agent holding nozzle 12. As a result, the cleaning agent 5 is discharged from the cleaning agent holding nozzle 12 through the cleaning agent discharge port 52, and the internal state of the dot marking and printing device 1 transitions from the state shown in Figure 6(X) to the state shown in Figure 6(Y). As shown in Figure 6(Y), even after performing the air process 93, the paint flow path 32 remains filled with the cleaning agent 5.

[0052] In the method of use 90 of the dot marking and printing system 60 according to this embodiment, a time interval can be provided between the sequential execution of the cleaning agent supply step 91, the depressurization step 92, and the air step 93, and the execution of the void spray step 94. After the execution of the above three steps, the paint flow path 32 in the discharge nozzle 11 is filled with cleaning agent 5 instead of paint 6. This is preferable because, as time passes, the paint 6 will not harden due to drying in the paint flow path 32 in the discharge nozzle 11. Even if the cleaning agent 5 evaporates, it will be replaced by air, so there will be no problem.

[0053] In the method of use 90 of the dot marking and printing system 60 according to this embodiment, after the cleaning agent supply step 91, the depressurization step 92, and the air step 93 are performed sequentially, a waste blowing step 94 is provided in order to perform the printing step again. In the waste blowing step 94, the discharge control valve 22 is kept open for a certain period of time or for 1 to 10 times. When it is kept open for 1 to 10 times, the opening time should be the same as the opening time when the paint 6 is discharged in the printing step. In the waste blowing step 94, the cleaning solenoid valve 74, the cleaning air solenoid valve 73, and the circulation solenoid valve 72 are closed, the paint supply stop solenoid valve 71 is open, and the depressurization device 62 is not operating.

[0054] The void spraying process 94 transitions the state from Figure 6(Y) to Figure 6(Z). As shown in Figure 6(Y), before the void spraying process 94, the paint channel 32 is filled with cleaning agent 5. However, the void spraying process 94 pushes the paint 6 in the paint chamber 2 into the paint channel 32 in the discharge nozzle 11, and as a result, the cleaning agent 5 filling the paint channel 32 is discharged from the discharge port 51. If the cleaning agent 5 has evaporated, the paint 6 simply fills the paint channel 32 in the discharge nozzle 11. The void spraying process 94 brings the system to the state shown in Figure 6(Z), making it possible to proceed to the printing process.

[0055] Next, as another embodiment of the present invention, a method of use 100 for the dot marking and printing system 60 will be described in detail. As shown in Figure 7, the method of use 100 sequentially includes a cleaning agent supply step 91, a compressed air introduction step 95, and a depressurization step 92 after the printing step. The method of use 100 then includes a waste spray step 94 after the depressurization step 92. The method of use 100 may include a time interval between the depressurization step 92 and the waste spray step 94. During the time interval, the dot marking and printing device 1 is not in use. The reason a time interval can be included is, as in the case of the method of use 90, that the discharge nozzle 11 is not filled with paint 6, so there is no risk of the paint 6 solidifying.

[0056] As shown in Figure 7, the cleaning agent supply step 91 in method of use 100 is the same as the cleaning agent supply step 91 in method of use 90, so its explanation is omitted. The cleaning agent supply step 91 reduces the paint pressure on the paint 6 in the paint chamber 2, which had been high due to the pressure pumping of the paint 6 into the paint chamber 2 by the paint pump 65, to approximately atmospheric pressure. At this time, the inside of the dot marking and printing device 1 transitions from the state in Figure 5(X) to the state in Figure 5(Y). In the state in Figure 5(Y), after the cleaning agent supply step 91 has been performed, the discharge nozzle 11 remains filled with paint 6.

[0057] As shown in Figure 7, the method of use 100 includes a compressed air introduction step 95 after the detergent supply step 91. In the compressed air introduction step 95, the discharge control valve 22, the cleaning solenoid valve 74, the circulation solenoid valve 72, and the paint supply stop solenoid valve 71 are all closed, and the cleaning air solenoid valve 73 is open. Also, the pressure reducing device 62 is not operating in the compressed air introduction step 95. The execution of the compressed air introduction step 95 of the method of use 100 transitions from the state in Figure 5(Y) to the state in Figure 8(X). In the state in Figure 5(Y), the detergent 5 was filled in the detergent holding nozzle 12, but in the compressed air introduction step 95, the detergent 5 is discharged from the detergent holding nozzle 12 through the detergent discharge port 52. Figure 8(X) shows the state after the detergent 5 has been discharged.

[0058] Furthermore, as shown in Figure 7, the method of use 100 includes a depressurization step 92 after the compressed air introduction step 95. The details of the depressurization step 92 are the same as those of the depressurization step 92 in the method of use 90 and are therefore omitted. The depressurization step 92 of the method of use 100 transitions from the state in Figure 8(X) to the state in Figure 8(Y). The paint 6 in the paint flow path 32 of the discharge nozzle 11 is drawn into the paint chamber 2 by depressurizing the paint chamber 2 to below atmospheric pressure and by opening and closing the discharge control valve 22, and the air in the cleaning agent holding nozzle 12 is drawn into the paint flow path 32 of the discharge nozzle 11. Since the amount of air drawn in each time is kept constant by appropriately designing the opening and closing of the discharge control valve 22 between 1 and 10 times, the amount of air drawn in can be controlled. The opening time of the discharge control valve 22 for the 1 to 10 openings and closings in this case may be the same as the time when the paint 6 for dot printing and marking is discharged in the printing process. By appropriately designing the number of times the discharge control valve 22 is opened and closed between 1 and 10 times, it is possible to suppress the amount of air drawn into the paint chamber 2, which is more preferable. The method of use 100 may also include performing a blow-out process 94 and a printing process as appropriate after the depressurization process 92.

[0059] Next, as another embodiment of the present invention, a method of use 110 for the dot marking and printing system 60 will be described in detail. As shown in Figure 9, the method of use 110 sequentially comprises a pressure return step 99, a second cleaning agent supply step 96, a second depressurization step 97, and a second air step 98. The method of use 110 may include a time interval after the second air step 98, after which a blow-off step 94 and a printing step may be performed as appropriate.

[0060] Method of use 110 uses a dot marking and printing system modified from the dot marking and printing system 60 shown in Figure 3 by removing the paint circulation piping 82 and the circulation solenoid valve 72. Since the paint circulation piping 82 is removed, in the dot marking and printing system according to this embodiment, the pressure reducing device 62 and the paint chamber 2 provided in the dot marking and printing device 1 are connected by the pressure reducing device piping 83. The reason why piping routes such as the paint circulation pipe 82 for circulating the paint 6 have been removed is because ink is used for the paint 6. If the paint 6 is not ink, solid matter may separate and settle from the paint 6, so circulation of the paint 6 is necessary, and therefore the paint circulation pipe 82 is required. However, if the paint 6 is ink, there is no risk of separation or settling of solid matter. Therefore, when using ink for the paint 6, it is more preferable to have a dot marking and printing system 60 with the paint circulation pipe 82 and other components removed.

[0061] Referring to Figure 9, the method of use 110 will first be described in detail, starting with the pressure relief process 99. In the pressure relief process 99, the discharge control valve 22 may be kept open for a certain period of time, or it may be opened 1 to 10 times repeatedly. It is preferable that the opening and closing be done for the same duration as when the discharge nozzle 11 discharges paint 6 for printing. In addition, in the pressure relief process 99, the cleaning solenoid valve 74, the cleaning air solenoid valve 73, and the paint supply stop solenoid valve 71 are closed, and the pressure reducing device 62 is not activated. The pressure relief process 99 reduces the pressure inside the paint chamber 2 to near atmospheric pressure.

[0062] Next, the second detergent supply process 96 will be described in detail. As shown in Figure 9, the second detergent supply process 96 is the same as the detergent supply process 91 except that the step of opening the circulating solenoid valve 72 is removed. The other steps are the same as those of the detergent supply process 91. As a result of the second detergent supply process 96, the state shown in Figure 5(X) changes to the state shown in Figure 5(Y), where the inside of the detergent holding nozzle 12 is filled with detergent 5, and a surface tension phenomenon occurs at the detergent discharge port 52, causing the detergent 5 to be held inside the detergent holding nozzle 12.

[0063] Next, the second depressurization step 97 of the method of use 110 will be described in detail. As shown in Figure 9, the second depressurization step 97 is the same as the depressurization step 92 except that the step of closing the circulating solenoid valve 72 is removed. The second depressurization step 97 causes the dot marking and printing device 1 to transition from the state shown in Figure 5(Y) to the states shown in Figure 5(Z) and Figure 6(X). In other words, the cleaning agent 5 is drawn into the paint flow path 32 of the discharge nozzle 11.

[0064] Next, the second air step 98 of the method of use 110 will be described in detail. As shown in Figure 9, the second air step 98 is the same as the air step 93 except that the step of closing the circulating solenoid valve 72 is removed. The second air step 98 causes the inside of the dot marking and printing device 1 to transition from the state shown in Figure 6(X) to the state shown in Figure 6(Y). In other words, the paint flow path 32 of the discharge nozzle 11 remains filled with the cleaning agent 5, while the cleaning agent 5 in the cleaning agent holding nozzle 12 is discharged to the outside of the dot marking and printing device 1 from the cleaning agent discharge port 52.

[0065] In the method of use 110, the state transitions from the state in Figure 6(Y) to the state in Figure 6(Z) by performing a waste spraying step 94 after the second air step 98. That is, the discharge control valve 22 opens, the cleaning agent 5 is pushed out of the dot marking and printing device 1 from the paint flow path 32 of the discharge nozzle 11 by the discharge port 51 and discharged, and paint 6 is supplied from the paint chamber 2 to the paint flow path 32 inside the discharge nozzle 11, making it possible to proceed to the printing step. A time interval may be provided between the second air step 98 and the waste spraying step 94 during which the dot marking and printing device 1 is not in use. During this non-use period, the paint flow path 32 is filled with cleaning agent 5, so there is no risk of nozzle clogging, which is preferable.

[0066] This disclosure can be suitably used for the purpose of printing or marking inspected printed objects. However, it is not limited to this, and can be broadly used in packages, inspected parts, and the like that require dot markings and printing. [Explanation of symbols]

[0067] 1. Dot-shaped marking and printing device 2,Paint room 3. Cleaning agent passage 5. Cleaning agent 6,Paint 10. Nozzle plate 11. Discharge nozzle 12. Detergent retaining nozzle 20, valve seat 21, valve body 22. Discharge control valve 23. Movable core 24, Vibration mechanism 25, sheet 30, Detergent flow path 31, wall part 32, Paint channel 51, Discharge port 52, Detergent discharge port 60. Dot-shaped marking and printing system 61. Compressed air supply source 62. Depressurization device 63, Paint Tank 64. Source of cleaning agents 65, Paint pump 66. Detergent pump 71. Paint supply stop solenoid valve 72. Circulating solenoid valve 73. Cleaning air solenoid valve 74. Washing solenoid valve 80, Compressed air piping 81, Paint piping 82, Paint circulation piping 83. Pressure reducing device piping 84, Cleaning agent piping 90,100,110,How to use 91. Detergent supply process 92. Depressurization process 93. Air process 94, Blow process 95. Compressed air introduction process 96. Second detergent supply process 97. Second depressurization process 98. Second air process 99. Pressure relief process

Claims

1. A dot marking and printing system comprising a dot marking and printing device equipped with a discharge nozzle for dispensing paint, a paint chamber, a cleaning agent passage, and a cleaning agent flow path, wherein the paint chamber is equipped with a discharge control valve consisting of a valve seat and a valve body, The aforementioned dot marking and printing system further includes a pressure reducing device and pressure reducing device piping. The paint chamber of the dot marking and printing device and the pressure reducing device are connected at least by the pressure reducing device piping. The dot marking and printing system is characterized in that the pressure reducing device is capable of reducing the pressure applied to the paint in the paint chamber to below atmospheric pressure.

2. A dot marking and printing device comprising a discharge nozzle for dispensing paint, a paint chamber, a cleaning agent passage, and a cleaning agent flow path, wherein the paint chamber is equipped with a discharge control valve consisting of a valve seat and a valve body, A compressed air supply source, compressed air piping connecting the compressed air supply source and the dot marking and printing device, and a cleaning air solenoid valve provided in the compressed air piping, A pressure reducing device, pressure reducing device piping connecting the pressure reducing device and the dot marking and printing device, paint circulation piping connecting the dot marking and printing device and the paint tank for circulating the paint, and a circulation solenoid valve provided in the paint circulation piping, The paint tank, paint piping connecting the paint tank and the dot marking and printing device for supplying the paint to the dot marking and printing device, a paint pump for pressurizing the paint in the paint piping, and a paint supply stop solenoid valve provided in the paint piping, A dot marking and printing system characterized by comprising a cleaning agent supply source, cleaning agent piping connecting the cleaning agent supply source and the dot marking and printing device for supplying the cleaning agent to the dot marking and printing device, and a cleaning solenoid valve provided in the cleaning agent piping.

3. A method for using the dot marking and printing system according to claim 2, A cleaning agent supply step for supplying the cleaning agent to the dot marking and printing device, The system includes a depressurization step for reducing the pressure in the paint chamber, The aforementioned detergent supply step and the aforementioned depressurization step are carried out sequentially. The cleaning agent supply step is a step of opening the cleaning solenoid valve, closing the cleaning air solenoid valve, opening the circulation solenoid valve, and closing the paint supply stop solenoid valve. A method for using a dot-shaped marking and printing system, characterized in that the depressurization step is a step of opening the discharge control valve for a certain period of time, a step of closing the cleaning solenoid valve, the cleaning air solenoid valve, the circulation solenoid valve, and the paint supply stop solenoid valve, and a step of operating the depressurization device to reduce the pressure of the paint in the paint chamber to a pressure lower than atmospheric pressure, all performed simultaneously.

4. The method of using the aforementioned dot marking and printing system further comprises a compressed air introduction step, The compressed air introduction step is a step of opening the cleaning air solenoid valve and closing the cleaning solenoid valve, the circulation solenoid valve, and the paint supply stop solenoid valve. The method for using the dot marking and printing system according to claim 3, characterized in that the cleaning agent supply step, the compressed air introduction step, and the depressurization step are carried out in order.

5. The method for using the dot marking and printing system according to claim 3 or 4, characterized in that the depressurization step comprises a step of repeatedly opening and immediately closing the discharge control valve one to ten times, instead of the step of keeping the discharge control valve open for a certain period of time.

6. A dot marking and printing device comprising a discharge nozzle for dispensing paint, a paint chamber, a cleaning agent passage, and a cleaning agent flow path, wherein the paint chamber is equipped with a discharge control valve consisting of a valve seat and a valve body, A compressed air supply source, compressed air piping connecting the compressed air supply source and the dot marking and printing device, and a cleaning air solenoid valve provided in the compressed air piping, A pressure reducing device, and pressure reducing device piping connecting the pressure reducing device and the dot-shaped marking and printing device, A paint tank, a paint piping connecting the paint tank and the dot marking and printing device for supplying the paint to the dot marking and printing device, a paint pump for pressurizing the paint in the paint piping, and a paint supply stop solenoid valve provided in the paint piping. A method for using a dot marking and printing system comprising a cleaning agent supply source, cleaning agent piping connecting the cleaning agent supply source and the dot marking and printing device for supplying the cleaning agent to the dot marking and printing device, and a cleaning solenoid valve provided in the cleaning agent piping, The aforementioned paint is an ink, The method of using the dot marking and printing system is as follows: A pressure relief step to return the pressure inside the paint chamber to near atmospheric pressure, A second cleaning agent supply step for introducing the aforementioned cleaning agent, It is equipped with a second depressurization step, The pressure release step, the second detergent supply step, and the second depressurization step are carried out in order. The pressure relief process involves simultaneously opening the discharge control valve 1 to 10 times, closing the cleaning solenoid valve, closing the cleaning air solenoid valve, and closing the paint supply stop solenoid valve. The second cleaning agent supply step is a step of opening the cleaning solenoid valve and closing the cleaning air solenoid valve and the paint supply stop solenoid valve, A method for using a dot-shaped marking and printing system, characterized in that the second depressurization step is a step of closing the cleaning solenoid valve, the cleaning air solenoid valve, and the paint supply stop solenoid valve, and activating the depressurization device to reduce the pressure of the paint chamber to a pressure lower than atmospheric pressure.

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