JPH0947717A - Steel plate marking method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the clogging of a nozzle during marking to perform marking always clear in the temperature range from room temperature to specified temperature. SOLUTION: In a marking method intended for a steel plate at temperature between room temperature and specified temperature using a double pipe nozzle 11 to keep a dot of ϕ4mm by an air atomizing method, after a compressed coating material fed from a coating material pressure adjusting valve 5 and discharged from a coating material discharge nozzle and compressed air fed from an air pressure adjusting valve 2 and discharged from an air/washing liquid discharge nozzle are mixed to perform marking, discharge switching control between a washing liquid from a washing liquid pressure adjusting valve 8 and air from the air pressure adjusting valve 2 is performed in order to prevent the clogging of the nozzle and defective print, before the next marking is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a method of marking a steel plate or the like in the temperature range of 2 by the air atomizing method.

[0002]

2. Description of the Related Art In general, a marking display on a steel plate or the like is a display of a specification required by a customer and is also used as a key for identifying an actual product on a trimming processing line after a shearing line in a factory. Clear and precise character display is required. Further, since it is installed in the main shear line directly connected to the rolling line, it must be a device with high equipment reliability that can process all of the strips with high efficiency in order to secure production processing.

FIG. 3 is a schematic configuration diagram of a conventional steel plate marking apparatus. At the time of marking, the needle valve 40 is opened, and pressurized paint is discharged from the paint nozzle 41, and at the same time, pressurized air is discharged from the air nozzle 42 to mix the paint and air, and the paint is atomized into a fine particle size. Then, the so-called air atomizing method of marking is performed by spraying on the marked surface 43 on the steel plate to form the marking dot coating 44 having a prescribed dot diameter.

FIG. 4 is a view showing a conventional two-fluid spray nozzle, and FIG. 4 (a) is an enlarged view of the nozzle tip portion.
(B) is a cross-sectional view of the tip of the nosol. In this case, for example, as shown in FIG. 4B, after the coating material is discharged from the coating material 50 to mark it on the steel plate, the cleaning liquid is discharged from the cleaning liquid nozzles 51 concentrically arranged on the outer periphery thereof. Wash the paint.

In the case of the example shown in FIG. 3, the paint has a boiling point of 1
A water-soluble paint with a high temperature of 00 ° C is used, and the air atomization method is used in the entire temperature range from normal temperature to high temperature. However, compared to organic paint, nozzle clogging is more likely to occur, so the nozzle diameter is necessarily It has to be big.

On the other hand, in the case of the example shown in FIG. 4, since the marking is performed by the airless method and the paint uses an organic system having a boiling point of 60 ° C., it is possible to handle from room temperature to 100 ° C. In the case of the above high temperature steel plate, the paint evaporates and it does not deposit on the steel plate, but it repels powder and marking becomes impossible.

[0007]

However, in the above-mentioned conventional example, for example, in the case of FIG. 3, since the marking by the air atomization method is performed, it is possible to perform marking of a high temperature material from room temperature to 300 ° C., but nozzle clogging is possible. Since the nozzle diameter must be increased for prevention, the dot diameter of the marking is inevitably increased, and there is a problem that clear marking is impossible when printing on thick plates.

Further, in the case of FIG. 4, since the water-soluble paint, which is likely to cause nozzle clogging when the drying time is slow during normal temperature printing, is replaced with an organic paint, the nozzle diameter can be made small, but airless There is a problem that it cannot be applied to a high temperature material of 100 ° C. or higher for printing.

Therefore, an object of the present invention is to provide a steel plate marking method capable of preventing nozzle clogging and always maintaining a dot diameter φ4 mm over the entire temperature range from room temperature to 300 ° C. to enable clear marking. To provide.

[0010]

The steel sheet marking method according to the present invention prevents nozzle clogging when marking on a steel sheet or the like in a temperature range from room temperature to 300 ° C. by the air atomization method, and prevents the nozzle from room temperature to 300 ° C. It is a steel plate marking method that enables a clear marking by always maintaining a dot diameter of φ4 mm over the entire temperature range.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION To achieve the above object, the invention according to claim 1 holds a dot of 4 mm in diameter by an air atomizing method using a double tube nozzle and keeps the temperature from room temperature to 30
In the marking method for steel plates up to 0 ° C,
A feature of the present invention is that discharge control of the cleaning liquid and the air is performed after marking is performed on the surface to be marked by discharging the paint from the paint discharging nozzle and air from the air / cleaning liquid discharging nozzle in the outer peripheral portion.

Further, the invention according to claim 2 is a marking method for a steel sheet from room temperature to 300 ° C. by holding a dot of φ4 mm by an air atomizing method using a double tube nozzle, The feature is that marking is performed by controlling the particle size of the paint sprayed from the tip of the nozzle depending on the temperature.

According to the first aspect of the present invention, after performing the marking of the air atomizing method in which the paint and the air are discharged and mixed, the cleaning liquid is discharged from the air / cleaning liquid discharge nozzle to perform cleaning, and then the next marking is performed. Since the discharge switching control for switching to the air discharge is performed immediately before the operation, it is possible to prevent nozzle clogging and defective printing and perform clear marking even with a high temperature material from room temperature to 300 ° C.

According to the second aspect of the present invention, the particle diameter of the paint sprayed from the tip of the nozzle is controlled so as to be changed according to the temperature of the material to be marked. It can be held at φ4 mm for clear marking.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a process diagram showing a method for controlling steel plate marking according to the first embodiment of the present invention.

In FIG. 1, 1 is an air compressor for air compression, 2 is a pressure adjusting valve for air, 3 is a solenoid valve for turning air on / off, 4 is a compressor for paint,
5 is a paint pressure control valve, 6 is a paint ON / OFF solenoid valve, 7 is a cleaning liquid compressor, 8 is a cleaning liquid pressure control valve, 9 is a cleaning liquid ON / OFF solenoid valve, and 10 is the temperature of the running steel plate. The radiation thermometer 11 is a double-tube nozzle having a paint discharge nozzle in the center and an air / cleaning liquid discharge nozzle on the outer periphery thereof for performing air atomizing marking.

Next, the operation will be described.

When marking on a running steel plate or the like by the air atomizing method, the air system compresses the air with the air compressor 1 and adjusts and sets the pressure with the pressure adjusting valve 2 to set the double pipe nozzle 11 Supply to the air / cleaning liquid discharge nozzle.

On the other hand, similarly in the paint system, the paint compressed by the paint compressor 4 is supplied to the paint discharge nozzle of the double pipe nozzle 11 after the pressure is adjusted and set by the pressure adjusting valve 5.

The paint pressure and air pressure set in this case are controlled by the temperature of the steel plate measured by the radiation thermometer 10. For example, when the steel plate temperature is high, the paint discharge pressure is lowered and the air discharge pressure is increased. And so on. The distance between the tip of the nozzle and the steel sheet is also adjusted according to the steel sheet temperature, and the distance between the steel sheets is controlled to become shorter as the temperature rises.

These compressed paints and compressed air are respectively discharged and mixed from the double tube nozzle 11 to form dots of a prescribed φ4 mm on a steel sheet by the dot spray method.

When the first marking is completed, the solenoid valve 3
And 6 are turned off to stop the supply of paint and air, the solenoid valve 9 is turned on to supply the cleaning liquid to the air / cleaning liquid discharge nozzle, and the double pipe nozzle 11 is cleaned to prevent nozzle clogging. Prepare for marking.

When the cleaning time has passed, the solenoid valve 9 is turned off to stop the supply of the cleaning liquid, and immediately before the next steel plate marking in the running marking, the solenoid valve 3 is turned on for a predetermined time to air the double pipe nozzle 11. Is supplied to blow away the remaining cleaning liquid and residual paint for cleaning.

After the nozzle 11 has been cleaned, the solenoid valve 6 is also turned on and compressed paint and compressed air are supplied to the double tube nozzle 11 in the same manner as at the beginning to mark the next steel plate.

The procedure of the above-mentioned discharge switching control can be simply summarized as follows.

Treatment 1, air / paint discharge mixture spraying, treatment 2, cleaning liquid discharge, treatment 3, air discharge immediately before the next marking, treatment 4, air / paint discharge mixture spraying at the time of the next marking. Becomes In addition, since the organic coating material having a boiling point of 60 ° C. is used in this embodiment, airless printing is performed in the normal temperature (˜90 ° C.) region and air atomized printing is performed in the high temperature (90 ° C. to 300 ° C.) region. It enables clear and clear marking.
In addition, since only the cleaning liquid is discharged and cleaned after marking, it is possible to prevent the cleaning liquid from accumulating in the nozzle tip due to surface tension, and to prevent the paint from drying and adhering to the nozzle due to the high temperature on the steel plate side and causing nozzle clogging. Immediately before the marking, the residual liquid is completely cleaned and the adverse effect on the marking is wiped off, so that clear marking can be performed.

Next, a second embodiment of the present invention will be described.

FIG. 2 is a diagram showing the relationship between the steel plate temperature and the paint particle size according to the second embodiment of the present invention.

In the second embodiment, the size of the atomized paint sprayed from the nozzle 11 is controlled by the temperature of the steel plate of the material to be marked. In order to reliably hold the dot diameter φ4 mm, which is a marking unit, paint and air are discharged from the double tube nozzle 11 and mixed, and marking is performed on a high temperature steel plate by air atomizing printing, but the temperature of the steel plate becomes high. As the particle size of the paint to be sprayed increases, the degree of evaporation becomes high, the degree of evaporation to a powder and the impossibility of being deposited on the steel plate increases, and the dot diameter φ4 mm cannot be maintained. Therefore, the indication of the radiation thermometer 10 becomes high. Therefore, it is necessary to reduce the paint particle size so as to maintain the dot diameter φ4 mm in the marking unit.

To reduce the paint particle size, a method such as increasing the air pressure is used. In FIG. 2, the vertical axis indicates paint.
Taking the particle size and taking the steel plate temperature on the horizontal axis, the optimum paint particle size was empirically obtained by actual measurement. As a result, the optimum paint particle size is The particle size is φ4 mm. When the plate temperature is 90 to 130 ° C, the paint particle size is φ2.0 to
2.5mm When the plate temperature is 130 ~ 170 ℃, the paint particle size is φ1.5 ~
2.0mm When the plate temperature is 170 ~ 200 ℃, the paint particle size is φ1.0 ~
1.5mm When the plate temperature is 200 ~ 300 ℃, the paint particle size is φ0.5 ~
It becomes 1.0 mm. In addition, this paint particle size is a measurement of the paint particle size at the time of contacting a steel plate. Finally, as a total, with the air atomizing printing method using the double tube nozzle 11, dot diameter φ4 mm, dot interval 5 mm, steel plate speed maximum 60 m
Table 1 shows the measured values of the optimum paint discharge pressure, air discharge pressure and paint particle size that enable clear marking under the condition that the pm and the steel plate temperature are in the range of normal temperature to 300 ° C.

As described above, according to the present invention, the dot diameter φ4 mm can be maintained by controlling the paint particle size to the optimum value, airless printing is performed in the normal temperature range (up to 90 ° C.), and air atomization is performed in the high tone range between 90 ° C. and 300 ° C. As a printing method, clear marking is possible in all temperature ranges, which is also suitable for printing on thick board products.

[0033]

[Table 1]

[0034]

As described above, according to the present invention as set forth in claim 1, after the marking by the air atomizing method for discharging and mixing the paint and the air, the cleaning liquid is discharged from the air / cleaning liquid discharging nozzle. Since the discharge switching control that switches to air discharge immediately before performing the next marking after cleaning is performed, nozzle clogging and marking defects can be prevented, and clear marking can always be performed over the entire temperature range from room temperature to 300 ° C. .

Further, according to the second aspect of the invention, since the particle size of the paint sprayed from the nozzle tip is controlled so as to be changed according to the temperature of the steel plate to be marked, the marking is always performed even when the steel plate temperature is in the high temperature range. Dot diameter φ4mm
Keeping at, clear marking is possible over the entire temperature range from room temperature to 300 ° C.

[Brief description of drawings]

FIG. 1 is a process diagram showing a method for controlling steel plate marking according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between paint particle diameter and steel plate temperature according to a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a conventional steel plate marking device.

FIG. 4 is a diagram showing a conventional two-fluid spray nozzle.

[Explanation of symbols]

 1 Air compressor 2 Air pressure adjusting valve 3, 6, 9 Solenoid valve 4 Paint compressor 5 Paint pressure adjusting valve 7 Cleaning liquid compressor 8 Cleaning liquid pressure adjusting valve 10 Radiation thermometer 11 Double pipe nozzle

Claims (2)

[Claims] 1. A double-tube nozzle is used to hold dots of φ4 mm by an air atomizing method, and the temperature is from room temperature to 300 ° C.
In the marking method for steel sheets up to, the paint is discharged from the paint discharge nozzle, and air is discharged from the air / cleaning liquid discharge nozzle in the outer peripheral part. A steel plate marking method characterized by the above. 2. A Φ4 mm dot is held by an air atomizing method using a double tube nozzle and the temperature is from room temperature to 300 ° C.
The method for marking a steel plate as described above, wherein the marking is performed by controlling the particle size of the paint sprayed from the tip of the nozzle according to the temperature of the marking target material.