JP2000015146A - Device and method for coating flat plate material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating device for flat plate materials capable of improving coating efficiency and improving appearance quality without the occurrence of unequal coating even when flat planar materials to be coated which have ruggedness on their surfaces with a large amt. of water-coating material and a coating method therefor. SOLUTION: In this coating method, on aq. emulsion coating material is continuously supplied from a continuous coating material supplying means 30 to an air gun 18 and prescribed voltage is impressed between an external wall panel plate material 10 and the air gun 18 to adsorb the foggy particulate portion of the discharged aq. emulsion coating material to the front surface side 10a. At this time, the atomization regulating air for regulating particle sizes is delivered in the direction of the discharged aq. emulsion coating material from the circumference a coating material discharge hole for discharging the aq. emulsion coating material by an air supplying means for supplying the atomization regulating air in a route separate from the route of the continuous coating material supplying means 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus and a coating method for a flat material which is mainly used for buildings and the like and which constitutes a wall surface.

[0002]

2. Description of the Related Art In recent years, a porous inorganic building material such as a lightweight cellular concrete panel or a wood chip cement plate has been used as an outer wall material constituting an outer wall surface of a prefabricated house such as a unit house. In order to improve the weather resistance of the surface of such a porous inorganic building material, a coating method of applying a water-based paint in consideration of the problem of environmental pollution using an electrostatic coating device has been developed (JP-A-4-197469). Gazette, JP-A-4-3
No. 00267, JP-A-5-15843, etc.).

In such a conventional apparatus, the water-based paint is atomized to form particles having a particle size of less than about 50 μm, so that these water-based paints are applied along an electrostatic force line generated by an applied DC high voltage. It is configured to adsorb onto the object to be coated while curving the path of the particles of the coating.

[0004]

However, in such a conventional method of applying a water-based paint using an electrostatic coating apparatus, as shown in FIG. In the wall panel 1 having the groove 3 having a predetermined height h1 (approximately 0.5 to 15 mm) as a decoration, the application width can be adjusted depending on the pressure discharged from the discharge hole of the water-based paint and the pinhole shape. Because of the difficulty, the discharge pressure from the discharge hole must be set to a high pressure so that almost the most of the water-based paint becomes fine particles suitable for electrostatic adsorption coating. In addition, the discharge pressure must be maintained at a constant high pressure in order to prevent a decrease in the application amount due to a change in temperature or a change in viscosity of the water-based paint.

As the amount of the water-based paint increases, the amount of the water-borne paint rebounds and atomizes on the surface side 2 as the amount of the water-based paint increases, and the amount of the water-borne paint dispersed in the atmosphere increases, and the amount of the paint applied decreases. Would. For this reason, it was difficult to make the ejection hole approach the front side 2.

In the case of using the electrostatic attraction method, the edge portions 4, 4 formed on the upper edges of the side wall portions 3b, 3b have
A water-based paint having fine particles is concentrated.

As described above, the water-based paint adhered to the edge portion 4 has a low viscosity state depending on the temperature conditions and the like, and there is a possibility that the water-based paint becomes water droplets and dripping 6 in the groove portion 3. Such a dripping 6 has a relatively small concave pattern 7.
However, when it is provided on the front side 2, the inside of the concave pattern 7 may be buried and the pattern may not be visible, and it is difficult to maintain the appearance quality.

The bottom 3a and the side wall 3 of the groove 3
b, 3b, so that the water-based paint does not easily reach the bottom portion 3a, etc., to which the thinnest coating is applied.
The amount of spray from the spray nozzle 5 must be set. Therefore, even if the adhesion rate is improved by electrostatic attraction,
With respect to the sprayed water-based paint, the amount of the effective adhesion paint for forming a coating film of a practical thickness was reduced, and the coating efficiency was not good.

Further, in order to shorten the coating time, it is conceivable to use an airless type spraying device which can spray a large amount from one spray nozzle 5. In this case, a paint piping system and an insulating seal portion that can withstand high pressure are required, and a structure capable of holding electric charges required for electrostatic attraction is required. And it is difficult to use it practically.

Further, as shown by a two-dot line in the drawing, it is conceivable to attach the spray nozzle 5 obliquely so that the water-based paint can reach the side wall 3b. In the reciprocating type which reciprocates along the edge, the overhang w must be set outside the wall panel edge 1a in order to apply the water-based paint also to the edge 1a of the wall panel 1. For this reason, there has been a problem that the lateral width of the entire coating apparatus is increased and space efficiency is reduced. Further, in the case where the spray nozzle 5 is swung, the manufacturing cost of the coating apparatus also increases.

In order to solve this problem, the inclination angle of the spray nozzle 5 is set to 10 degrees or more when the inside of the groove 3 is painted, and when the flat part on the front side 2 is painted,
The applicant has proposed a method in which the angle of inclination is changed in two stages to 10 degrees or less and the individual coating is performed (Patent Registration No. 25).
40226). However, in the method of performing the coating twice at different angles in this manner, two coating machines must be provided, and there is a problem that the manufacturing cost of the coating apparatus increases.

In addition, at the edge 1a on the opposite side of the wall panel 1, the water-based paint sprayed from the spray nozzle 5 attached at an angle as shown in FIG.
However, as the distance h2 apart from the wall panel 1 increases, the area increases in a substantially elliptical shape in the horizontal plane. For this reason,
As shown by the dashed line in the drawing, the horizontal stop position of the spray nozzle 5 is slightly shifted to the outside by s, and the amount of waste that does not adhere to the wall panel edge 1a and exceeds the wall panel edge 1a increases. There was also a problem that the coating efficiency was not good.

Further, when a large amount of water-based paint is discharged from one spray nozzle 5, the water-based paint rebounds and atomizes on the front side 2 and is dispersed in the atmosphere, thereby reducing the amount of adhesion. Also in this respect, it has been difficult to improve the coating efficiency.

An object of the present invention is to solve the above-mentioned problems, and to improve the coating efficiency and reduce unevenness in coating even when a large amount of water-based paint is applied to a flat object having irregularities on the surface. An object of the present invention is to provide a coating apparatus and a coating method for a flat plate material that can improve the appearance quality without causing the generation.

[0015]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a conveying means for conveying an object having a substantially flat surface, and an aqueous paint is applied to the surface of the object. A reciprocating coating machine for reciprocating a plurality of air guns to be ejected toward the direction substantially perpendicular to the conveying direction of the object to be coated; a continuous coating means for continuously supplying a water-based coating to the air gun; An electrostatic attraction means for applying a predetermined voltage between the air guns to adsorb the atomized fine particles of the discharged water-based paint on the surface of the object to be coated, a paint discharge hole for discharging the water-based paint, and the paint From the periphery of the discharge hole, toward the direction of the aqueous paint to be discharged, a plurality of air nozzles having an atomization adjustment air discharge hole that sends out atomization adjustment air for adjusting the particle diameter of the aqueous paint, are provided in the air gun, The airnos The atomization adjusting air supplied to, and the coating material continuously supply means is characterized in the coating apparatus of the flat plate provided with an air supply means for supplying a different route.

According to the first aspect of the present invention, the particle diameter of the water-based paint is adjusted to a size suitable for adhering to the surface of the workpiece by the atomizing air supplied by the air supply means. Be prepared. For example, particles having a median particle diameter of 50 μm or more go straight from a paint discharge port formed in the air gun and adhere to the surface side of the object to be coated. For this reason, even if the electrostatic attraction is performed by the electrostatic attraction means, the ink reaches the side wall and the bottom without being attracted to the edge portion of the uneven portion, and the desired coating film thickness can be quickly increased with the same discharge amount. Can be formed.

Further, the pressure of the water paint discharged from each air gun can be set lower than that discharged from one air gun when the same amount of water paint is applied to the same area. In addition, since a plurality of air nozzles are provided for each air gun, the amount of rebound can be reduced even when the air nozzles are ejected close to an object having a substantially planar surface. By bringing the air gun closer to the surface of the object to be coated, the amount of the water-based paint scattered in the air is further reduced, and the coating efficiency can be improved.

Further, even if the direction of discharge of the paint from the air gun is set substantially perpendicular to the surface of the object to be coated, for example, the particles of the water-based paint reach the side walls of the groove and the like, and have a substantially uniform thickness. In addition, a coating film can be formed. Further, since a substantially uniform coating film is formed even in a relatively small concave pattern, it is possible to maintain the pattern and maintain good appearance quality without causing dripping as in the related art.

In addition, the air supply means supplies the atomized air to be supplied to the air nozzle through a separate path from the paint piping system of the continuous paint supply means. By using a low pressure-resistant pipe or the like and discharging the paint from the paint discharge port at a low pressure, the amount of the water-based paint that rebounds on the surface side of the workpiece is further reduced. Further, it is possible to obtain a configuration capable of retaining the electric charge required for electrostatic attraction without escaping without using an expensive high-voltage insulating sealing material or the like.

For this reason, it is possible to stably adjust the particle size of the water-based paint while suppressing an increase in the production cost, and obtain a desired coating amount.

Further, the water-based paint atomized into fine particles and the water-based paint splashed on the surface of the object to be coated are electrostatically adsorbed to the object to be coated by the electrostatic means, and the water-based paint having the adjusted particle diameter is obtained. By applying the water-based paint of the atomized fine particles on the effective coating film secured by the paint, the coating efficiency can be further improved and the appearance quality can be improved. At this time, the moisture in the coating film previously adhered to the surface side of the object to be coated, the adsorption-side charge is charged substantially uniformly, and the atomized water-based paint is almost uniformly adsorbed. It is possible to obtain a two-layer coating film having a substantially uniform thickness on any painted surface by a single application of the water-based paint, without being affected by irregularities and edges.

For this reason, the air gun is brought close to the object to be coated, or the pattern width is set to be narrow, with almost no consideration of the amount of the paint that rebounds and forms a mist, so that the direct hit rate to the object to be coated is reduced. By improving the coating efficiency, the coating efficiency can be further improved, and the amount of coating material coming off the edge of the object to be coated with a narrow pattern width can be reduced even when the discharge direction is inclined. Therefore, even if an air gun inclined to be used for painting the vertical wall surface of the uneven portion is provided, the painting efficiency is maintained at a good level, and the overhang amount is reduced, and a flat material having a good space efficiency is obtained. Can be provided.

According to the second aspect of the present invention, the paint continuous supply means communicates with a paint discharge port of the air gun through a paint supply system pipe, and has a storage tank made of an insulating material. The storage tank is slidable in a horizontal direction to a position opposed to a receiving portion at an upper portion of the storage tank. In the opposed state, conduction is performed so as to have substantially the same potential as that of the storage tank, and the aqueous paint inside the storage tank is removed. And an intermediate tank receiving a paint supply from the main paint tank when the separated paint is separated from the main paint tank.

According to the second aspect of the present invention, the intermediate tank which has received the paint supply while being separated from the main tank is slid in the horizontal direction, and the intermediate tank is slid in the horizontal direction. When you reach the opposing position,
Conduction is performed so that the potential is substantially the same as that of the storage tank.
Therefore, the water-based paint in the intermediate tank flows down and is stored without having a potential difference with the paint in the storage tank. When the intermediate tank slides to the separated state again after the flow of the water-based paint, the intermediate tank is insulated from the storage tank and is now at the ground potential, and the supply of the water-based paint from the main tank is performed by the electrostatic attraction means. Can be performed without stopping the application of the voltage. For this reason, even if the storage tank is in communication with the paint supply system piping, the storage tank can always be filled with the water-based paint and the object can be continuously coated.

Further, since the storage tank is insulated, the storage tank is miniaturized so that the charge applied by the electrostatic suction means does not escape, and the volume of the water-based paint to which a voltage is applied is reduced. Thereby, the electrostatic adsorption efficiency can be further improved, and the space efficiency can be improved.

According to the third aspect,
3. The flat plate coating apparatus according to claim 2, wherein the paint continuous supply means has a color change valve capable of switching a communication destination to a plurality of storage tanks.

According to the third aspect of the present invention, the color change valve provided in the continuous paint supply means switches the communication destination to a plurality of storage tanks.
For this reason, if a different color paint is put in each storage tank, a plurality of colors of paint can be changed and used in correspondence with the object to be coated.

According to the present invention, a shape detecting sensor for detecting the shape of the object to be coated is provided along the reciprocating direction of the reciprocating coating machine, and the shape is detected by the shape detecting sensor. When the air gun passes over the shape portion of the object to be coated, the water discharge paint is discharged from the paint discharge hole in an ON state, and when the air gun passes through a portion having no object to be coated, the paint discharge hole is turned on. 4. A flat plate coating apparatus according to claim 1, wherein said coating apparatus is in an OFF state in which no water-based paint is discharged.

According to the fourth aspect of the present invention, when the air gun passes through a portion where there is no object to be coated, the water-based paint is not discharged from the paint discharge hole by the shape detection sensor. So, for example,
Even with a deformed object to be coated such as a trapezoidal wall panel, the water-based paint can be applied to the surface side with high coating efficiency.

Further, according to the present invention, when the object to be coated having a substantially planar surface is conveyed and the aqueous paint is discharged from a plurality of air guns toward the surface of the object to be coated, A reciprocating coating method of reciprocating in a direction substantially perpendicular to the conveying direction of the object to be coated, and a water-based paint is continuously supplied from the paint continuous supply unit to the air gun,
By applying a predetermined voltage between the object to be coated and the air gun by the electrostatic suction means, and adsorbing the atomized fine particles of the discharged water-based paint to the surface of the object to be coated, the paint continuous supply means Is a mist that adjusts the particle diameter of the aqueous paint from the periphery of the paint outlet for discharging the aqueous paint toward the direction of the aqueous paint to be discharged by air supply means that supplies the atomization adjustment air through another path. The method is characterized by a method of coating a flat plate material that sends out the conditioning air.

According to the fifth aspect of the present invention, even if there is a change in the specific gravity or the like due to a change in the viscosity and temperature of the water-based paint or a change in color, the air supply means constituted by another path is used. In this way, the particle distribution can be easily adjusted to be stable, and the coating efficiency can be improved by forming a coating film almost uniformly without being affected by the conductivity on the surface side of the object to be coated. Can be done.

[0032]

Embodiment 1 Next, Embodiment 1 of the present invention
Will be described with reference to the drawings. Parts that are the same or equivalent to those in the conventional example will be described with the same reference numerals.
In the first embodiment shown in FIGS. 1 to 12, an outer wall panel board 10 constituting an outer wall of a building unit of a unit house
There is provided a coating device 13 for coating a flat material for coating the surfaces such as to 12. The coating device 13 is provided with a belt conveyor 14 as a conveying means. The belt conveyor 14 is configured so that the substantially planar surface of the outer wall panel 10 is placed substantially horizontally, and is conveyed by driving a chain 14a.

The belt conveyor 14 is provided with an undercoating machine 15 and an overcoating machine 16. Of these, the undercoating machine 15 has substantially the same configuration as the above-mentioned topcoating machine 16, and therefore the description is omitted. The top coater 16 is a reciprocating coater that reciprocates in a direction substantially perpendicular to the direction in which the belt conveyor 14 is conveyed inside a spray chamber 16a that is provided so as to straddle the belt conveyor 14 and is formed in a substantially box shape. It has a main body 17. The reciprocating coater main body 17 is provided with a plurality of air guns 18 for discharging the aqueous emulsion paint toward the front side 10a of the outer wall panel 10 or the like. In the first embodiment, eight air guns are provided. Are suspended along a reciprocating coating apparatus main body 17 and fixed to a substantially rod-shaped support 19 which is driven reciprocally.

Each of these air guns 18 has a pair of air nozzles 20, 20. This air nozzle 20
As shown in FIGS. 9 and 10, is formed of a metal conductor, and has a paint discharge hole 21 for inwardly inward at a predetermined angle with respect to the air gun center line m and for discharging the aqueous emulsion paint. Have been. Further, the air nozzle 20 is provided with an atomizing air to incline from around the paint discharge hole 21 toward the direction of the aqueous emulsion paint to be discharged and adjust the particle diameter of the aqueous emulsion paint. A plurality of atomization adjusting air discharge holes 22, 22 to be sent out are provided.

Further, the air nozzle 20 is provided with a plurality of pattern air discharge holes 23, 23 inclining in the direction of the aqueous emulsion paint to be discharged and adjusting the width to which the aqueous emulsion paint is applied. Have been.

These air guns 18 are connected to a paint continuous supply means 30 for continuously supplying an aqueous emulsion paint to the paint discharge holes 21. The paint continuous supply means 30 communicates with the paint discharge port 21 of the air gun 18 through a paint supply system feed pipe 31 and a paint supply system return pipe 32 formed of an insulating material. A storage tank 33 made of a material is provided. This storage tank 33 is placed on a voltage block 34 insulated from the ground plane. That is,
In FIG. 7, a lower portion of a metal frame 35 is sufficiently grounded by a ground 36. This frame 35
The storage tank 33 is placed via a voltage block 34 at the lower part of the storage tank 33.

The storage tank 33 has a frame 35
A paint pump 38 for supplying paint is connected to the paint supply system feed pipe 31 which is supported via an insulating support 37, and is driven in the direction of the paint discharge hole 21 by the rotation of an electric motor 39. Is configured to be pumped. The surplus paint is returned to the storage tank 33 via the paint supply system return pipe 32 supported by the frame 35 via the insulating support 40.

In the first embodiment, the storage tank 3
3 is set to about 50 liters.

On the upper surface 33a of the storage tank 33,
A stirring motor 42 for stirring the paint in the storage tank 33.
Is provided. An upper limit sensor 43 and a lower limit sensor 44 for detecting the amount of paint in the storage tank 33 are provided on the upper surface portion 33a. The upper limit sensor 43 and the lower limit sensor 44 are connected via lead wires 46 to a control panel 50 provided at the upper corner of the frame 35. The control panel 50 is configured to receive power supply from a power supply 150 and to control various power supplies by an internal power supply control circuit 50a.

A funnel-shaped receiving portion 45 is provided adjacent to the stirring motor 42 and opens upward.
When the water-based paint in the intermediate tank 47 flows down into the storage tank 33 in a state facing the intermediate tank 47, the receiving portion 45 is connected to a lower discharge port 48a formed in a lower opening / closing valve 48 of the intermediate tank 47. On the other hand, the water-based emulsion paint is configured to have a wide mouth so as to flow down without being scattered even in a state of being separated in a substantially vertical direction.

The intermediate tank 47 has a plurality of stays 51.
, And a tip of a cylinder rod 53 of a cylinder device 52 is connected to the stay 51. The cylinder device 52 includes a branch pipe 61a branched from an oil supply valve 61 extending from the control panel 50.
Are connected to perform hydraulic pressure supply control. And
In the upper part of the storage tank 33, the intermediate tank 47 is horizontally moved along the upper rail 49 from a position facing the receiving portion 45 to a separated position shown by a two-dot chain line in FIG. It is configured to be slidable along with the sliding of 53.

In the first embodiment, the intermediate tank 4
7 is set to about 10 liters. The intermediate tank 47 is electrically connected to the storage tank 33 through the conductive member 100 provided on the voltage block 34 so as to have substantially the same potential as that of the storage tank 33 in the facing state. When flowing down, it prevents the generation of sparks and the like, and in the separated state, it becomes a ground potential and discharges unnecessary charge when receiving paint supply from the main paint tank 54 connected via the supply pump 54a. Is configured to be reduced.

In the upper part of the intermediate tank 47, in the separated state, the paint outlet 5 provided below the butterfly valve 55 provided above the upper rail 49 is provided.
6, a paint supply opening 57 is provided.

The butterfly valve 55 includes a branch pipe 61 b branched from the oil supply pipe 61 to the control panel 50.
And is opened and closed by hydraulic control from the control panel 50, and is connected to the paint pressure regulator 58 from the main paint tank 54.
The water-based emulsion paint supplied through the tank is allowed to flow down only when the intermediate tank 57 is at the ground potential.

Further, an upper limit sensor 59 is provided above the intermediate tank 47, and is connected to the control panel 50 via a lead wire 60. The butterfly valve 55 is configured to close when the aqueous emulsion paint reaches a specified amount.

Then, these overcoating machines 16 ...
As shown in FIG. 6, five units are provided on the insulating voltage block 8 for each of the aqueous emulsion paints of different colors and are arranged in the direction in which the belt conveyor 14 extends. The feed pipe 31 of the paint supply system of each top coater 16 is individually connected via a manual pressure regulator valve 62,
It is connected to the color change valve 63. The color change valve 63 includes a flow meter 64 and the control panel 5.
The air gun 20 is connected to a paint discharge hole 21 formed in an air nozzle 20 of the air gun 18 via a remote regulator 65 connected to the air gun 18. The color change valve 63 is also connected to a small-lot compatible top coater 116 and a water tank device 216 for cleaning.

In the coating apparatus 16, the control panel 50 is connected to the air supply means 70 through the lead wires 71 and 72.
Are connected to the airflow switches 73 and 74 of the first embodiment. The air flow switch 73 is connected to the air nozzle 2.
The compressed air supplied from a compressor 78 through an air pressure regulator 76 and a drainer 77 under the control of the control panel 50, while being connected to the atomization adjusting air discharge holes 22. By adjusting the air pressure and discharging the water-based emulsion paint in a different path from the water-based emulsion paint toward the discharged water-based emulsion paint, the water-based emulsion paint is discharged. It is configured to adjust the particle size of.

The air flow switch 74 is connected to the pattern air discharge holes 23 of the air nozzle 20 via an air hose 79, and through an air pressure regulator 76 and a drain remover 77 under the control of the control panel 50. The compressed air pressure supplied from the compressor 78 is adjusted so that the compressed air is discharged from the pattern air discharge holes 22 in a different path from the aqueous emulsion paint toward the discharged aqueous emulsion paint. Thus, the width of the aqueous emulsion paint applied to the front side 10a of the outer wall panel board 10 or the like is adjusted.

Then, a predetermined voltage is applied between the object to be coated, such as the outer wall panel 10 and the air gun 18, and the sprayed fine particles of the aqueous emulsion paint are applied to the coating device 16. An electrostatic attraction means 80 for attracting the outer wall panel plate 10 to the front surface 10a is provided.

The electrostatic attraction means 80 includes the control panel 5
A DC high voltage generator 81 is connected between the air nozzles 20 and 20 and the outer wall panel 10 to apply a high voltage of about 70 kv. The DC high-voltage generator 81 is connected to the air nozzle 20 via a high-voltage cable 82, and is also connected to an overcurrent detector 83 and a voltage regulator 84. Note that reference numeral 85 in FIG. 1 denotes a shield line.

In the top coater of the first embodiment, a plurality of shape detecting sensors 16c are arranged at predetermined intervals at the entrance 16b of the spray chamber 16a in a direction perpendicular to the driving direction of the belt conveyor 14. Is provided over substantially the entire width. These shape detection sensors 16c are connected to the control panel 50, respectively.
In addition to recognizing the shape of the outer wall panel 10 or the like that moves on the vehicle 4, the water-based emulsion paint discharged from the paint discharge holes 21 is turned ON and OFF under the control of the remote regulators 65. .

Next, the operation of the first embodiment will be described with reference to the steps of manufacturing the outer wall panel 10 and the like.

In the first embodiment, a plurality of grooves 3 and concave patterns 7 are formed as decorations along the belt conveyor 14 and have a substantially planar surface side 10a to 1a.
When the outer wall panel plates 10 to 12 having 2a are conveyed rightward in FIG. 6 from the spray chamber of the undercoating machine 15 and approach the entrance 16b of the spray chamber 16a of the overcoating machine 16, the shape detection sensors 16c. Thereby, the presence or absence of the passing outer wall panel boards 10 to 12 is detected.

The detected presence / absence signal is sent to the power supply control circuit 50a of the control panel 50, and is converted into ON / OFF signals of the remote regulators 65. Control the operation individually.
Then, the portion where the outer wall panel materials 10 to 12 exist,
When an air gun 18 provided on a reciprocating coating machine main body 17 that reciprocates in a direction substantially orthogonal to the belt conveyor conveyance direction passes, an ON signal is sent to the corresponding remote type regulator 65 to transmit the paint discharge holes 21. , 21 from which aqueous emulsion paint is discharged
An air gun 18 provided on a reciprocating coating machine main body 17 for reciprocating a portion having no outer wall panel materials 10 to 12 in a direction substantially perpendicular to the belt conveyor passage passes while the so-called ON state in which discharge is performed in two directions. To turn off the corresponding remote regulator 65
A signal is sent to turn off the aqueous paint from the paint discharge holes 21 and 21. The discharge flow rate is monitored and fed back for each air gun 18 by the valve flow meters 64.

For this reason, for example, the trapezoidal wall panels 11, 1
Even when the object to be coated such as 2 is deformed, when the air gun 18 passes over the object to be coated at the portion indicated by the one-dot chain line in FIG. The water-based emulsion paint is ejected toward the object and applied, and as shown by a one-dot chain line in FIG.
At a position deviating from above the object to be coated, the aqueous emulsion paint is turned off and is not ejected from the air gun 18, so that the amount of the aqueous emulsion paint that does not directly contact can be reduced.
Can be applied to the surface sides 11a and 12a with a coating amount corresponding to the approximate area amount with high coating efficiency.

The particle size of the aqueous emulsion paint to be applied is adjusted to a size suitable for adhesion to the surface of the object to be coated by the atomization adjusting air supplied by the air supply means 70. For example, particles having a medium or larger particle diameter of 50 μm or more go straight from the paint discharge port formed in the air gun 18 and adhere to the surface sides 10 a to 12 a of the outer wall panel boards 10 to 12. For this reason, even if the electrostatic attraction by the electrostatic attraction means 80 is performed, the aqueous emulsion paint reaches the side wall 3b and the bottom 3a without being attracted to the edge 4 of the groove 3 which is the uneven portion, and A desired coating film thickness can be formed quickly with the same discharge amount. FIG. 14 shows that the particle diameter of the paint is determined in the regions Ia, Ib, II, III
Are shown in FIG. this house,
The boundary between region Ib and region II is about 50 μm,
The aqueous emulsion paint having a particle diameter belonging to the region II has high straightness. Further, the aqueous emulsion paint having a particle diameter belonging to the region Ib has a particle diameter that is not good at reaching the object to be coated, but has a high adsorption rate by the electrostatic adsorption means 80.

The pressure of the aqueous emulsion paint discharged from each air gun 18 can be set lower than that discharged from one air gun 18 when the same amount of the water paint is applied to the same area. . Moreover, since a plurality of air nozzles 20 are provided for each of the air guns 18, even if the air nozzles 20 are ejected in close proximity to an object having a substantially planar surface, the amount of rebound can be reduced. Then, by bringing the air gun 18 close to the surface of the object to be coated, the amount of the water-based emulsion paint scattered in the air is further reduced, and the coating efficiency can be improved. As described above, in the spray type coating machine that discharges the aqueous emulsion paint from the paint discharge hole 21 at a constant pressure, as shown in FIG. 13, the paint viscosity and the like are known as the coating efficiency factor. FIG. 19 shows the relationship between the distance h2 between the air gun 20 and the object to be coated and the coating efficiency. In this case, it can be seen that the closer the distance h3 is, the more the coating efficiency is improved. FIG.
0 indicates the relationship between the nozzle size and the coating efficiency.
In this case, it can be seen that the coating efficiency is further improved by increasing the nozzle size and the discharge amount. FIG. 21 shows the relationship between the moving speed of the air gun 20 and the coating efficiency. In this case, it is understood that the lower the moving speed of the air gun 20, the higher the coating efficiency.

In the first embodiment, the water-based emulsion paint having a particle diameter of about 50 μm or more belonging to the region II has a predetermined coating amount which exhibits waterproofness and weather resistance, for example, 150 to 400 g / m 2. It can be formed in a shorter time as compared with electrostatic coating in which the distribution amount of fine particles having a particle diameter of less than about 50 μm belonging to the regions Ia and Ib is large. For this reason, as in the first embodiment, it is suitable for coating the front side 10a to 12a of the outer wall panel materials 10 to 12 having a large area to be coated, and as shown in FIG. Can be increased to about 2.4 to 3.8 m / min to further improve the coating efficiency.

Further, even if the paint discharge direction from the air gun 20 is set substantially perpendicular to the surface of the object to be coated, for example,
As shown in FIG. 11, particles of the water-based paint can reach the side walls and the like of the groove 3 to form a coating film with a substantially uniform thickness.
In addition, since a substantially uniform coating film is formed even in the relatively small concave pattern 7, the pattern can be maintained and the appearance quality can be maintained satisfactorily without causing dripping as in the related art. FIG.
In each of Examples 4 to 6 shown in FIG. 8, the air gun 20 faces the surface to be coated at 90 degrees in the roll direction and at 70 degrees in the pitch direction. In this case, any of Examples 4 to 6 can form a favorable substantially uniform coating film. For this reason, the overhang amount on both the left and right sides of the spray chamber 16a is reduced as compared with the conventional one, so that the whole apparatus can be downsized and the space efficiency is good.

Further, the air supply means 70 feeds the atomizing air supplied to the air nozzle 20 to the paint supply system feed pipe 31 and the paint supply system return pipe 32 of the paint continuous supply means 30. Since the supply is performed using the air hose 75 or the like in a separate path from the system, a low-pressure-resistant pipe or the like is used for the insulating seal portion of the continuous paint supply means 30, and the paint is discharged from the paint discharge port 21 at low pressure. By doing so, the amount of the water-based emulsion paint that rebounds on the surface side 10a to 12a of the outer wall panel boards 10 to 12 is further reduced.

Further, it is possible to obtain a configuration capable of retaining the electric charge required for electrostatic attraction without escaping without using an expensive high-voltage insulating sealing material or the like.

Therefore, it is possible to stably adjust the particle size of the aqueous emulsion paint while suppressing an increase in the production cost, and obtain a desired coating amount.

Moreover, in the first embodiment, as in the first to third embodiments shown in FIG.
While a pressure of 2.0 kgf / square cm or more is applied, a low pressure of less than 2.0 kgf / sq.
The atomizing air is supplied at a pressure of 2 to 0.8 kgf / square cm. As shown in FIG. 15, when the atomizing air pressure and the pattern air pressure are set high and around 2.0 kgf / cm 2,
The distribution is biased toward the region Ib in FIG. Therefore, in order to obtain a highly linear particle diameter, the supplied air pressure is
A low value is desirable. However, as shown in FIG. 16, even if the application amount is reduced, the particles in the region Ib do not completely disappear, and in the case of a large discharge amount exceeding 570 g / min shown in FIG. By lowering the number, the number of particles in the region near 50 μm can be reduced, but the number of particles increases again in the working area near 30 μm.

Therefore, the water-based emulsion paint atomized into fine particles and the water-based emulsion paint splashed on the surface sides 10a to 12a of the outer wall panel boards 10 to 12 are further subjected to the electrostatic adsorption means 80 to form the water-based emulsion paint. Side 10a
11a to 12a, the fine particles in FIG. 11 are marked with a negative mark on the effective coating film secured by the aqueous emulsion paint having the adjusted particle diameter schematically represented by a water droplet shape in FIG. By adhering these atomized fine particle aqueous emulsion paints expressed by the formula (1), the coating efficiency can be further improved and the appearance quality can be improved.

At this time, first, the outer wall panel plates 10-1
The water in the coating film adhered to the surface sides 10a to 12a of the No. 2 substantially uniformly charges the adsorption side charge +, and the water-based emulsion paint having the atomized-mark is almost uniformly adsorbed.
It is possible to obtain a two-layer coating film having a substantially uniform thickness on any painted surface by a single application of the aqueous emulsion paint, without being affected by the unevenness of the outer wall panel materials 10 to 12, the edge portion 4, the concave pattern 7, and the like. . That is, on the surface sides 10a to 12a of the outer wall panel boards 10 to 12 on which the coating film is formed first, substantially the same conductivity is given to almost the entire surface by the water content of the aqueous emulsion paint. Side 1
It is not affected by the change in the electrical conductivity from 0a to 12a. For this reason, even if the dry and wet states of the front side 10a to 12a are different depending on the coating order, it is possible to form the coating film substantially uniformly, and it is good even if the curing time is not constant depending on the storage or shipping order. Appearance quality and coating efficiency can be further improved.

For this reason, the distance h3 is set to 250 mm, which is shorter than the conventional distance h2, as in Examples 1 to 3 shown in FIG. The air gun 18 may be brought closer to the front side 10a to 12a of the outer wall panel members 10 to 12, or the pattern width may be set to 2 as in the embodiments 4 to 6 shown in FIG.
By setting it to 30 to 290 mm narrower than the conventional one and improving the direct hit rate to the object to be coated, the coating efficiency can be further improved and the discharge direction can be inclined by setting the pitch angle to 70 degrees. In addition, the amount of paint that has come off from the end 1a of the outer wall panel plate 1 with a narrow pattern width can be reduced. Further, since a narrow pattern width can be set, even if the horizontal stopping position of the spray nozzle 5 is slightly shifted by s, and the reciprocating coating machine main body 17 reciprocates outwardly,
The amount of deviation from the end 1a can be reduced.

Therefore, a recovery device for the aqueous emulsion paint is not required, and the coating efficiency can be improved even if the air gun 18 inclined for use in coating the vertical side wall surface 3b of the uneven groove 3 is provided. Maintain, and Figure 22
Can reduce the overhang amount W shown in (1) and can provide a coating apparatus for a flat plate material with good installation space efficiency.

Further, in the first embodiment, as shown in FIG. 9, a pair of air nozzles 21 and 21 provided at the tip of the air gun 18 respectively have an angle α,
Since the nozzles oppose each other at the discharge direction angle of α, even if the discharge amount is increased by the two air nozzles 21 and 21, the discharged aqueous emulsion paint can directly improve the hit rate without being dispersed.

In the first embodiment, a total of 4 to 8 air guns 1 are mounted on the long support 19 of the reciprocating coating machine main body 17.
Since the number 8 is provided, even when the coating area per unit is small, the water-based emulsion paint can be applied by reciprocating in a short time on the large-area outer wall panel boards 10 to 12. For this reason, even if the drive speed of the chain 14a of the belt conveyor 14 is set high, the required coating film pressure can be obtained evenly. Also,
With the shape detection sensor 16c, the outer wall panel plates 10-1
When the interval between the two is widened, the discharge of the aqueous emulsion paint from the air gun 18 can be stopped, so that the drive speed of the chain 14a can be kept constant and the line operation rate can be improved. Moreover, it is not necessary to stop the reciprocating drive of the reciprocating coating machine main body member 17 and the stroke in the same width direction can be always reciprocated.
The mechanism can be simplified and the failure rate can be reduced.

Further, the intermediate tank 47 which has received the paint supply in a state of being separated from the main tank 54 is slid in the horizontal direction so as to face the receptacle 45 of the upper surface 33a of the storage tank 33 shown by a solid line in FIG. When you reach the position where
Conduction is performed so that the potential is substantially the same as that of the storage tank 33.

For this reason, the aqueous emulsion paint in the intermediate tank 47 flows down and is stored without having a potential difference from the residual aqueous emulsion paint in the storage tank 33. When the intermediate tank 47 slides again to the position shown by the two-dot chain line in FIG. 7 after the flow of the aqueous emulsion paint, the intermediate tank 47 is insulated from the storage tank 33 and then becomes the ground potential. ,
Supply of the aqueous emulsion paint from the main tank 54,
This can be performed without stopping the application of the voltage of the electrostatic attraction means 80.

For this reason, even if the storage tank 33 is connected through the paint supply system feed pipe 31 and the paint supply system return pipe 32, the storage tank 33 is always filled with the aqueous emulsion paint and continuously. Then, the outer wall panel boards 10 to 12 can be coated.

In addition, the coating efficiency is improved substantially in proportion to the applied voltage. Embodiment 1 The storage tank 33 is made of an insulating material made of a synthetic resin and is insulated, so that the storage tank 33 is protected from the charge applied by the electrostatic suction means 80 from escaping. By miniaturizing and reducing the volume of the aqueous emulsion paint inside which the voltage is applied, a relatively high applied voltage of about 70 kev
, And the electrostatic adsorption efficiency can be further improved. By reducing the size of the storage tank 33, space efficiency can be improved.

Further, the main tank 54 and the intermediate tank 4
7, the aqueous emulsion paint having a substantially constant temperature and a substantially constant viscosity is continuously supplied. For example, when the discharge pressure from the paint discharge hole 21 is less than 4 MPa,
Even if the pressure is set substantially near MPa, a change in the flow resistance in the paint supply system feed pipe 31 due to a temperature change or a viscosity change of the aqueous emulsion paint is small, and a substantially constant paint supply amount can be obtained.

For this reason, the amount of paint discharged from the paint discharge hole 21 is always kept substantially constant, and the particle size distribution is adjusted by adjusting the atomizing air pressure of only the air supply means 70 provided separately. The area can be roughly determined. Therefore, it is easy to increase the amount of particles in the region II having the highest coating efficiency, thereby increasing the coating efficiency.

Further, since the particle distribution stability is good even with respect to changes in specific gravity and viscosity, it can be applied to any specific gravity and viscosity.

As shown in FIG. 12, the color change valve 6 provided in the paint supply system feed pipe 31 and the paint supply system return pipe 32 of the paint continuous supply means 30 is provided.
3 and 63 switch communication destinations to the plurality of storage tanks 33. For this reason, if a different color paint is put in each storage tank 33, a plurality of colors of paint can be changed and used in correspondence with the outer wall panel boards 10-12. At this time, since the particle distribution stability is good, substantially the same appearance quality can be obtained even if there is a difference in specific gravity and viscosity due to a change in color.

Although the first embodiment of the present invention has been described in detail with reference to the drawings, the specific structure is not limited to the first embodiment, and there are design changes and the like within a range not departing from the gist of the present invention. Even this is included in the present invention.

For example, in the first embodiment, the pair of air nozzles 20 provided on the air gun 18 are configured to simultaneously discharge the aqueous emulsion paint. However, the present invention is not limited to this. By controlling the discharge, the particle size of the water-based paint to be discharged can be adjusted by air, such as performing coating with good coating efficiency adapted to the shape of the object to be coated. The number, shape, and ejection direction are not particularly limited as long as they are present.

[0080]

As described above, according to the first aspect of the present invention, the particle diameter of the water-based paint is reduced by the atomization adjusting air supplied by the air supply means. It is adjusted to a size suitable for adhesion. For example, particles having a median particle diameter of 50 μm or more go straight from a paint discharge port formed in the air gun and adhere to the surface side of the object to be coated. For this reason, even if the electrostatic attraction is performed by the electrostatic attraction means, the ink reaches the side wall and the bottom without being attracted to the edge portion of the uneven portion, and the desired coating film thickness can be quickly increased with the same discharge amount. Can be formed.

The pressure of the water-based paint discharged from each air gun can be set lower than that discharged from one air gun when the same amount of water-based paint is applied to the same area. In addition, since a plurality of air nozzles are provided for each air gun, the amount of rebound can be reduced even when the air nozzles are ejected close to an object having a substantially planar surface. By bringing the air gun closer to the surface of the object to be coated, the amount of the water-based paint scattered in the air is further reduced, and the coating efficiency can be improved.

Further, even if the paint discharge direction from the air gun is set substantially perpendicular to the surface of the object to be coated, for example, the particles of the water-based paint can reach the side walls of the groove and the like to have a substantially uniform thickness. In addition, a coating film can be formed. Further, since a substantially uniform coating film is formed even in a relatively small concave pattern, it is possible to maintain the pattern and maintain good appearance quality without causing dripping as in the related art.

Further, since the air supply means supplies the atomization adjusting air supplied to the air nozzle through a separate path from the paint piping system of the paint continuous supply means, the insulating seal portion of the paint continuous supply means By using a low pressure-resistant pipe or the like and discharging the paint from the paint discharge port at a low pressure, the amount of the water-based paint that rebounds on the surface side of the workpiece is further reduced. Further, it is possible to obtain a configuration capable of retaining the electric charge required for electrostatic attraction without escaping without using an expensive high-voltage insulating sealing material or the like.

Therefore, it is possible to stably adjust the particle size of the water-based paint while suppressing an increase in production cost, and obtain a desired coating amount.

Further, the water-based paint atomized into fine particles and the water-based paint splashed on the surface of the object to be coated are electrostatically adsorbed on the object to be coated by the electrostatic means, and the water-based paint having the adjusted particle diameter is obtained. By applying the water-based paint of the atomized fine particles on the effective coating film secured by the paint, the coating efficiency can be further improved and the appearance quality can be improved. At this time, the moisture in the coating film previously adhered to the surface side of the object to be coated, the adsorption-side charge is charged substantially uniformly, and the atomized water-based paint is almost uniformly adsorbed. It is possible to obtain a two-layer coating film having a substantially uniform thickness on any painted surface by a single application of the water-based paint, without being affected by irregularities and edges.

For this reason, the air gun can be brought close to the object to be coated or the pattern width can be set to be narrower without substantially considering the amount of the paint that rebounds and becomes mist, so that the direct hit rate to the object to be coated can be reduced. By improving the coating efficiency, the coating efficiency can be further improved, and the amount of coating material coming off the edge of the object to be coated with a narrow pattern width can be reduced even when the discharge direction is inclined. Therefore, even if an air gun inclined to be used for painting the vertical wall surface of the uneven portion is provided, the painting efficiency is maintained at a good level, and the overhang amount is reduced, and a flat material having a good space efficiency is obtained. Can be provided.

According to the second aspect of the present invention, the intermediate tank which receives the paint supply in a state of being separated from the main tank is slid in the horizontal direction so as to oppose the receptacle at the upper part of the storage tank. When it reaches the position, it is conducted so as to have substantially the same potential as the storage tank. Therefore, the water-based paint in the intermediate tank flows down and is stored without having a potential difference with the paint in the storage tank. When the intermediate tank slides to the separated state again after the flow of the water-based paint, the intermediate tank is insulated from the storage tank and is now at the ground potential, and the supply of the water-based paint from the main tank is performed by the electrostatic attraction means. Can be performed without stopping the application of the voltage. For this reason, even if the storage tank is in communication with the paint supply system piping, the storage tank can always be filled with the water-based paint and the object can be continuously coated.

Further, since the storage tank is insulated, the storage tank is miniaturized so that the charge applied by the electrostatic suction means does not escape, and the volume of the water-based paint to which a voltage is applied is reduced. Thereby, the electrostatic adsorption efficiency can be further improved, and the space efficiency can be improved.

And, according to the third aspect,
A color change valve provided in the paint continuous supply means switches a communication destination to a plurality of storage tanks. For this reason, if a different color paint is put in each storage tank, a plurality of colors of paint can be changed and used in correspondence with the object to be coated.

According to the fourth aspect of the present invention, when the air gun passes by the shape detection sensor when the air gun passes through a portion where there is no object to be coated, the water paint is not discharged from the paint discharge hole. For example, in the case of a deformed object to be coated such as a trapezoidal wall panel, the amount of the water-based paint that is not directly applied to the object to be coated can be reduced in the OFF state by not discharging, and the surface of the object to be coated can be reduced. A water-based paint can be applied with high coating efficiency.

Further, according to the fifth aspect of the present invention, even if there is a change in the specific gravity due to a change in viscosity and temperature or a change in color of the water-based paint, the use of the air supply means constituted by another path allows the particles to be dispersed. It can be easily adjusted to stabilize the distribution, and the coating efficiency can be improved by forming a coating film almost uniformly without being affected by the conductivity of the surface side of the object to be coated. It has a practically useful effect.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a coating apparatus and a coating method for a flat plate material according to a first embodiment of the present invention, and illustrating the configuration of the apparatus.

FIG. 2 is a schematic diagram illustrating a configuration of a flat plate coating apparatus according to the first embodiment.

FIG. 3 is a cross-sectional view of the flat panel coating apparatus according to the first embodiment, taken along a line AA in FIG. 2 of the spray chamber.

FIG. 4 is a cross-sectional view of the spraying chamber at a position along a line BB in FIG. 2 of the flat panel coating apparatus according to the first embodiment.

FIG. 5 is a partial cross-sectional top view of the spray chamber, illustrating the flat-plate coating apparatus according to the first embodiment.

FIG. 6 is a schematic diagram viewed from above illustrating an arrangement of a wall panel production line provided with a top coater and the like in the flat panel coating apparatus of the first embodiment.

FIG. 7 is a side view of a top coater in the flat plate coating apparatus according to the first embodiment.

FIG. 8 is a schematic view from above illustrating a relationship between a locus of an air gun and an object to be coated in the flat plate coating apparatus according to the first embodiment.

FIG. 9 is a partial cross-sectional view illustrating a configuration of an air gun used in the flat panel coating apparatus according to the first embodiment.

FIG. 10 is a front view of an air nozzle portion of an air gun used in the flat panel coating apparatus according to the first embodiment.

FIG. 11 is a schematic diagram illustrating a state in which an object to be coated having irregularities is coated by the flat plate coating apparatus according to the first embodiment.

FIG. 12 is a circuit diagram of a paint supply system provided with a color changer in the flat plate coating apparatus according to the first embodiment.

FIG. 13 is a table illustrating general characteristics of the airless coating machine.

FIG. 14 is a table illustrating a distribution of paint particle diameters.

[FIG. 15] Using the flat plate coating apparatus of the first embodiment,
FIG. 4 is a table based on actual measurements for explaining the distribution of paint particle diameters when a large amount of coating is set.

FIG. 16 shows an example of a flat plate coating apparatus according to the first embodiment.
FIG. 4 is a table based on actual measurements for explaining a distribution of paint particle diameters when an application amount is set to be slightly smaller.

FIG. 17 is a table summarizing Examples 1 to 3 of the first embodiment;

FIG. 18 is a table summarizing Examples 4 to 6 of Embodiment 1 in consideration of various conditions such as a gun speed and a conveyor speed.

FIG. 19 is a graph showing the relationship between general spray distance and coating efficiency.

FIG. 20 is a graph showing a general relationship between nozzle side and coating efficiency.

FIG. 21 is a graph showing the relationship between general gun speed and coating efficiency.

FIG. 22 is a schematic diagram illustrating a state of application to an object to be coated when a conventional electrostatic attraction coating machine is used.

FIG. 23 is a schematic diagram illustrating a state in which an object to be coated is applied to an edge portion when a conventional electrostatic suction coating machine is used.

[Explanation of symbols]

 Reference Signs List 3 groove part 3b side wall part 7 concave pattern 13 coating device 14 belt conveyor (conveying means) 16 top coater 17 reciprocating coater main body 18 air gun 20 air nozzle 21 paint discharge hole 22 atomization adjustment air discharge hole 23 pattern air discharge hole 30 paint continuous Supply device Paint supply system pipe 31 Paint supply system feed pipe 32 Paint supply system return pipe 33 Storage tank 33a Upper surface (upper part) 45 Receptacle part 47 Intermediate tank 50 Control panel 54 Main tank 63 Color change valve 70 Air supply means 80 Electrostatic Suction means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yuichiro Okamoto 54 Shimobuchi, Sakai-machi, Sawa-gun, Gunma Prefecture Sekisui Chemical Co., Ltd. (72) Inventor Seiji Nishisaka 2-4-12 Nakazaki Nishi, Kita-ku, Osaka-shi, Osaka Inside Sekisui Engineering Co., Ltd. (72) Inventor Hirohisa Iida 1259, Izumi, Miguchiguchi-cho, Koka-gun, Shiga Prefecture Inside Sekisui Chemical Co., Ltd. F term (reference) 4F033 EA05 JA08 QA01 QB03X QF01X 4F034 AA03 BA14 BB04 BB05 CA11 DA08 DA11 DA22 4F035 AA03 BC06 CA05 CC01 CD02

Claims (5)

[Claims] 1. A conveying means for conveying an object having a substantially planar surface, and a plurality of air guns for discharging a water-based paint toward the surface of the object to be coated are substantially orthogonal to the conveying direction of the object. A reciprocating coating machine for reciprocating in the direction, a continuous paint supply means for continuously supplying a water-based paint to the air gun, and applying a predetermined voltage between the object to be coated and the air gun to form a mist of the discharged water-based paint. Electrostatic attraction means for adsorbing the fine particle portion on the surface of the object to be coated; a paint discharge hole for discharging the water-based paint; and the periphery of the paint discharge hole toward the direction of the water-based paint to be discharged. The air gun is provided with a plurality of air nozzles having an atomization adjustment air discharge hole for sending atomization adjustment air for adjusting the particle diameter of the paint, and the atomization adjustment air supplied to the air nozzle is provided with the paint continuous supply means. Provided by another route An apparatus for coating a flat plate material, comprising: an air supply means for supplying air. 2. The paint continuous supply means communicates with a paint discharge port of the air gun through a paint supply system pipe.
A storage tank made of an insulating material, slidable in a horizontal direction to a position opposed to a receptacle at an upper portion of the storage tank, and in the opposed state, conductive so as to have substantially the same potential as the storage tank. 2. The flat plate according to claim 1, further comprising an intermediate tank for causing the water-based paint inside to flow down into the storage tank, and in a separated state, being at ground potential and receiving a paint supply from the main paint tank. Equipment for coating materials. 3. A flat plate coating apparatus according to claim 2, wherein said paint continuous supply means has a color change valve capable of switching communication destinations to a plurality of storage tanks. 4. A reciprocating coating machine along a reciprocating direction,
A shape detection sensor for detecting the shape of the object to be coated is provided, and a water-based paint is discharged from the paint discharge hole when the air gun passes over a shape portion of the object to be coated detected by the shape detection sensor. 4. An OFF state in which an aqueous paint is not discharged from the paint discharge hole when the air gun passes through a portion where there is no object to be painted, in an ON state. Flat plate coating equipment. 5. When conveying an object to be coated having a substantially planar surface and discharging a water-based paint from a plurality of air guns toward the surface of the object to be coated, the water-borne paint is substantially orthogonal to the conveying direction of the object to be coated. A reciprocating coating method for reciprocating in a direction, wherein a water-based paint is continuously supplied to the air gun from a paint continuous supply means, and a predetermined voltage is applied between the object to be coated and the air gun by an electrostatic suction means. When the atomized fine particle portion of the discharged water-based paint is adsorbed on the surface of the object to be coated, the water-based paint is discharged by air supply means for supplying atomization adjustment air in a different path from the continuous paint supply means. A spraying air for adjusting the particle diameter of the water-based paint is sent from around the paint-discharge hole to the direction of the water-based paint to be discharged.