JPH03267164A - Coating system and coating device - Google Patents

Abstract

PURPOSE:To allow the execution of various sprays by constituting the device in such a manner that the pressure of the coating material to be supplied to a coating gun can be regulated as desired and installing a washing device to this device. CONSTITUTION:A flow rate regulating circuit 38 is held for a low pressure by selection of shuttle valves 39, 40 in the halt state with a booster pump 37 as a passage in the case of application of an air spray system. The coating material of an assigned color is supplied through a color changer 54 and the flow rate regulating circuit to the coating gun 1 while the coating material is supplied under an assigned pressure from a coating material pump 35. The coating material is controlled at an assigned flow rate by retreating of a needle valve 5 and is injected like a filament from a nozzle 7. Pressurized air is supplied and the filamentous gushing material is atomized and sprayed by the air ejected in a cylindrical air nozzle 19. An initial cost is reduced in this way and coating efficiency is improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to painting the body of an automobile, which not only has a complicated shape, but also uses a painting robot to paint a wide variety of types while being transported by a conveyor. The present invention relates to a coating method and a coating device suitable for coating applications in which multiple coatings are applied using spray coating using a wide range of paints, and frequent color changes are required according to the order of demand.

[Conventional technology]

When painting an automobile body, for example, first a base coat is applied by electrodeposition, an intermediate coat is applied to a thickness of about 25 microns using a soufflé coating, a top coat is applied to a thickness of about 20 microns, and then a clear coat is applied. 30 by paint
A finishing coat of about microns is applied, but the thickness of the coating formed by one airless spray coating is 10
The desired thickness of the paint film from one air spray coating is about 3 microns, and for finish coating and clear coating, the film thickness is limited to air spray that is thin in one spray. For coating with a film thickness of 75 microns, spray coating can be repeated about 20 times.

A painting robot is installed on a painting line where the objects to be painted are transferred by a conveyor and painted one after another, and the painting process described above is carried out over many times.
Airless spray paint machines and air spray paint machines not only have different paint guns, but also have significantly different paint and air pumping conditions, so it is necessary to provide separate supply equipment for each, and most of the time, they are not installed in the painting line. Separate painting areas are provided for intermediate coating using airless spray painting and top coating areas for top coating and finishing using air spray coating. Also, since the coating methods for various equipment related to this are different, it is natural that equipment costs will be high if most of the equipment is installed as a separate painting station in the painting line, rather than a scale that needs to be installed separately. If both types of painting machines are installed in a common painting station for potash and trenches, the equipment becomes extremely complicated.

By the way, for example, when carrying out the topcoating process by air spraying 10 times or more, it may be sufficient to apply thick coating by airless spraying for the initial coating film formation for several times, and it is recommended to partially introduce such airless spraying. If it were possible to do this, painting efficiency would be significantly improved, but to do so, it would be necessary to install an airless spray tank equipment in the top coating equipment, and the paint would have to be changed frequently due to color changes. Since the properties of the paint generally differ depending on the type of paint used, it is important to adjust the spray type and various conditions for spraying in order to obtain a good paint film.

Therefore, an object of the present invention is to provide a coating method and a coating apparatus that can carry out various types of spraying, such as an airless spray method, an air spray method, and an air addition spray method that incorporates the advantages of both souffle methods. There is a particular thing.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an airless sprayer.
In addition to adopting a paint gun that is compatible with Air NuFray and air-addition spray, the pressure of the paint supplied to the paint gun can be adjusted to any pressure from low pressure suitable for air spray to high pressure suitable for airless spray. Also, the pressure of the air supplied to the coating gun can be adjusted to an arbitrary pressure of about 97d from 0 to 10, and a device for cleaning the paint supply route and the coating gun. By attaching a controller, it is possible to correspond to color changes, and by switching the color change device and cleaning device, the desired paint can be selected, and at the same time, the paint can be painted under the paint pressure corresponding to the applicable spray method. By supplying air to the gun and supplying air to the painting gun either without supply or under appropriately adjusted pressure, it is possible to apply intermediate coats, top coats including metallic paints, and finishes. To make it compatible with any type of painting such as painting.

First, as a paint nozzle for the paint gun, we adopted a kaorifice type flat spray nozzle that does not generate tails and has good atomization effect even when spraying low-pressure paint under airless conditions. In addition to providing air nozzles that eject from the surrounding area to the front, additional air nozzles are provided to supply air from outside of the spray to control the shaping of the spray.
The combination of changing the pressure of the supplied paint and selectively feeding and changing each air nozzle is made to correspond to any one type of spraying, such as airless spraying, air spraying, and air-additional spraying.

Regarding air supply, in addition to supporting air addition type spray, 10 kq/cr is also available to support air spray.
&A pressurized air supply source and pressure regulator should be provided so that paint can be supplied under any pressure below, and paint can be supplied at a pressure of approximately 10 kq/cyd or less using a low-pressure pump compatible with air spray. In order to supply paint to the painting gun under a low pressure while adjusting it to an appropriate pressure using a low pressure pressure regulator, and supplying paint under a high pressure suitable for airless spray or air-addition spray. In this case, a booster pump is connected in series with the low pressure pump, and the booster pump pumps 10 to 1
It is possible to supply paint pressurized to about 0.00 &9 /cl, and further adjust the pressure to an appropriate pressure using a pressure regulator for high pressure before supplying it to the painting gun.

[For production]

With the above configuration, several coats of paint can be applied without supplying air.
It is possible to inject a fan-shaped spray from a paint nozzle under a relatively high pressure of about kg/d or more in an airless spray system, and it is possible to spray from the outer periphery of the spray by such an airless spray. By supplying the control airflow, the airflow surrounds the fan-shaped spray and impinges on the spray to improve atomization and prevent the scattering of mist droplets,
Therefore, even though the paint film is relatively thick, a uniform paint film is formed with high transfer efficiency, and the paint nozzle still has three coats of paint.
kg/c1. At the same time, air is supplied at a relatively low pressure of about 9/cr& to produce a nearly strip-shaped jet from the paint nozzle, and at the same time, air is supplied at a relatively high pressure of about 9/cr& from the circumference of the paint nozzle. As a result, a cone-shaped spray is injected under one air spray system, and a fan-shaped spray can be obtained by supplying shaping air streams from both sides as necessary.

〔Example〕

Hereinafter, the present invention will be explained in detail using the illustrated coating apparatus.

1 to 3 illustrate the head of a painting gun 1 applied to the present invention, and show a valve seat 3 at the tip of the gun body 2.
The attached valve seat member 4 is screwed in a liquid-tight manner, and the needle valve 5 corresponding to the valve seat 3 is provided so as to be able to move forward and backward in the front-rear axis direction at a timely manner. 6
In addition to providing a holder 8 with an orifice-type flat paint nozzle 7 fitted to the tip of the valve seat member 4 near the interposition of the backing 9, the holder 8 The air nozzle member 10 was fitted together with the valve seat member 4 from the outside! ! ,Ma,
A nut 1 attached to the base end of this air nozzle member 10
1, it is fixed to the gun body 2. The gun body 2 is provided with air supply passages 12, 12 and 13, 13 in the front and rear direction in a portion near the axis and a portion near the outer periphery, respectively, and a valve seat member 4.
The flange of the holder 8 is provided with air supply passages 1.4, 14 and 15.degree. 15 in the front and rear direction which communicate with the air supply passage 12.degree. Correspondingly the air nozzle member 10. There is a catch groove 17
are engraved so that the attitude of the paint nozzle 7 is regulated so that fan-shaped spray is ejected vertically by the engagement of these protrusions 16 and the receiving grooves 17. A conical jet nozzle 18 that narrows forward is provided in the central front part of the air nozzle member 10, and a tapered cylindrical air nozzle 1 is provided between the jet nozzle 18 and the holder 8.
9, and on the outside of this air nozzle 19, auxiliary jet ports 20, 20, 21, 21 are arranged in a row in the diametrical direction, and auxiliary jet ports 22, 22 are arranged in parallel in an arc shape, and further air The nozzle member 10 is symmetrically provided with forward protrusions 23, 23 on both outer sides of its front end surface, and
Both protrusions 23.23 are provided with obliquely forward-facing flattening blowholes 24.24 facing inward.
An air supply passage 25.25 communicating with the air supply passage 24 is provided so as to communicate with the air supply passage 13.25 in the gun body 2.

As the paint nozzle 7, for example, Japanese Patent Application No. 128128
Preferably, the tailless nozzle disclosed in the above application or a nozzle having the same effect as the tailless nozzle disclosed in the above application has a substantially semicircular inclined plane portion 27. A cylindrical flow tube having a deformed dome-shaped concave surface 28 with 27 facing each other, and an elongated front end with crescent-shaped fan-shaped steps 29, 29 formed on both sides of the arcuate rear end of the concave surface 28. In addition to connecting the channel 30 with the cylindrical channel 30 in a rear open state based on a common axis relationship, the concave surface 28 is located at a close front and rear position including the straight edge of the inclined plane portion 27, and is connected to the cylindrical channel 30. Obtuse corner portions 31 and 31 without fillets are symmetrically formed near the connecting portion, and the nozzle body 2
A groove 32 with a V-shaped cross section is cut into the front end of the groove 32 in a front open state and at a depth such that the groove slightly intersects from slightly before the corners 31 and 31 intersect in the vicinity of the center. It has a structure in which a lip-shaped nozzle 33 is opened, and the tail generation prevention effect is remarkable and the atomization efficiency is good.

Further, as shown in FIGS. 7 to 9, an auxiliary inclined surface is formed near the base end of the semicircular inclined plane part in the nozzle shown in FIGS. 4 to 6, so that corner portions 31, 31 A front corner portion 34.34 is formed parallel to the front corner portion 34.34, and the groove 32 is formed to a depth such that the valley thereof coincides with or slightly intersects with the front corner portion 34.34,
For other configurations, it is preferable to adopt a nozzle similar to that shown in FIGS. 4 to 6. Other suitable nozzles for the present invention include Jitsuken 1-=27881 Publication and Jitsuken 2
-Nozzle described in Publication No. 5881 or JP-A-63-
There is a nozzle described in Publication No. 178867.

As for the equipment for pressurized paint supply to the painting gun 1, as shown in FIG. The paint pump 35.35 selectively supplies the paint through the color change device 36 and pressurizes it to a high pressure suitable for airless spraying as necessary with the intervention of an air-driven booster pump 37, and then adjusts the flow rate. The paint is supplied to the paint supply path 6 in the painting gun 1 via the adjustment circuit 38.

The paint pump 35 is operated at a relatively low pressure, for example 50 kp/c.
rfl or less, and the booster pump 37 pumps the pressurized paint pressurized and pumped by the paint pump 35 at 50 to 150 kg/cm as necessary.
By adopting air-driven plunger pumps for both pumps 35 and 37 and using pressurized air for power and pump 17, A desired paint pressure can be obtained by supplying the pressurized air while adjusting its pressure, and by further providing a pressure regulator on the discharge side, a more accurate pressure can be obtained. Note that the flow rate adjustment circuit 38 provided at the subsequent stage is connected to the low pressure flow path 4 by means of shuttle valves 39 and 40.
1 and the high-pressure flow path 42, and a low-pressure flow control valve 43 and a high-pressure flow control valve 44 are separately provided in these two flow paths. A flow meter 45 is provided, and the results detected by the flow meter 45 are inputted to a control device 46 and compared with a flow rate set in advance in the control device 46, and flow control valves 42, 43 are operated so as to obtain the same flow rate as the set value. In addition, a pressure regulating valve 47 is provided in the pressurized air supply path for driving the booster pump 37, and the paint pressure is adjusted based on the adjustment of the supply air pressure. Adjust the air supply so that the supply Said pump 35.
The pump 37 may be a fluid pressure driven pump such as a diaphragm pump.

Regarding the pressurized air still supplied to the painting gun 1,
In addition to supplying air to the air supply path 48 to the actuator for driving the needle valve 5 forward and backward, pressurized air for atomization is supplied to the air supply path 12 12 through an air supply path 49 . Air supply passage 50 supplies pressurized air for spraying and flattening to passage 13.13.
The pressurized air for atomization and spray flattening is supplied under desired conditions by adjusting the pressure and flow rate in the middle of the air supply path.

As for the color changing device 36 and related cleaning facilities, the mass color changing device 36 includes color changing valves 51, 51 and thinner valves 5 in number according to the number of colors of paint, as shown in FIG.
2 and an air valve 53 are arranged in parallel on the manifold 54, and the Fusta pump 37 is connected to the discharge side of the manifold 54.
It is connected to the discharge side of color B, and the thinner valve 52 is connected to the discharge side of the thinner pump 55.

A cleaning switching device 56 is interposed between the booster pump 37 and the 7-yattle valve 39 to simply allow paint to flow through during normal painting, but the color changing device 36 and booster pump 37 are connected during cleaning. It is desirable to shorten the cleaning time by dividing the cleaning path into two cleaning paths: a cleaning path and a path from the cleaning switching device 56 to the painting gun 1 via the flow rate adjustment circuit 38. 56 as a trigger valve 57. Dump valve 58. Thinner valve 59. An air valve 60 is installed in parallel to the manifold 61, and the booster pump 3
In addition to connecting the discharge side of the thinner valve 59 to the trigger valve 57, the thinner valve 59 is also connected to the discharge side of the thinner pump 55, so that during painting, between the dump valves and the thinner valve 59.
The trigger valve 57 is kept open while the air valve 6o is closed to allow paint from the booster pump 37 to flow directly to the nyatle valve 39. On the other hand, during cleaning, the trigger valve 5 is kept open.
7 is closed and the dump valve 58 is opened, and the thinner valve 52 and air valve 53 in the black color change device 36 are opened and closed alternately, and the trigger valve 57 and dump valve 58 are supplied from the color change device 36 via the booster pump 37. The interior is cleaned with thinner and air and discharged from the discharge passage 62, and the thinner valve 59 and air valve 53 in the cleaning switching device 56 are alternately opened and closed to flush the area from the cleaning switching device 56 to the painting gun 1 with thinner. Furthermore, the coating gun 1 is provided with a dump valve 63 so as to communicate with the paint supply path 6, so that cleaning liquid etc. can be discharged in addition to discharge only from the nozzle 7.

In addition, the surface near the front end of the paint gun 1 tends to attract paint droplets and gradually accumulate as it is used, which may interfere with spraying, so it is necessary to clean it appropriately. A cleaning device 64 is preferably provided.

In addition to the above, improved atomization 1 improved coating efficiency.

In order to prevent reduction of the spray angle, etc., it is desirable to apply an electrostatic coating method, and for this reason, as shown in Figures 1 to 3,
The air nozzle member 10 is provided with a needle electrode 65 protruding forward and inward from the protrusion 23 on one side.
A high voltage is applied from a high voltage power source (not shown) through the safety high resistance 66, conductor wire 67, and connection wire 68 inside the gun body 2, and the paint nozzle reflex itself is used as an electrode without providing a needle electrode. Alternatively, a high voltage may be applied to the paint nozzle 7.

As the flowmeter 45, it is preferable to adopt an impeller-type flowmeter installed in the flow path and to detect the flow rate by counting the Z-rus generated as the impeller rotates. To explain the case of painting based on the configuration, first of all, when applying the one-way air spray method, the booster pump 37
Under the rest state in which the is a mere passage, and by switching the shuttle valves 39 and 40, the flow rate adjustment circuit 38 is held for low pressure as shown in the figure, and paint of a specified color is supplied to the paint pump 3.
5 to the color changing device 54 while discharging under a specified pressure. Booster pump 37. Cleaning switching device 56. Flow rate adjustment circuit 38
The needle valve 5 is retracted to control the flow rate to the specified flow rate by the low-pressure flow rate control valve 43, and the flow rate is controlled to a specified flow rate by the low-pressure flow rate control valve 43. 0 to 10 in the air supply path 49.50
Approximately 1 to 2 kg/d of pressurized air is supplied, and the air ejected from the cylindrical air nozzle 19 atomizes the strip-shaped sprayed paint. , 21 , 21 , 22.22 and air supply from the flattening layer blowhole 24.24, the same atomization effect and spray flattening effect as in the conventional air spray type can be achieved. and to be able to obtain a fan-shaped spray.

Next, when applying the airless spray type, the paint pumped from the paint pump 35 of the designated color is transferred to the color change device 36 while the supply of pressurized air to the air supply path 49,50 in the paint gun 1 is stopped. The booster pump 37 pressurizes and supplies the water from
By switching the shuttle valves 39 and 40, pressure is sent to the coating gun l via the flow rate adjustment circuit 38 maintained for high pressure, and the needle valve 5
Under the retraction of the flowmeter 45. Control device 46. The paint, which is controlled at a specified flow rate by the high-pressure flow control valve 44, is injected under high pressure from the nozzle 7.Moreover, since the nozzle 7 is an orifice-type flat blowing nozzle that does not generate a tail, it is sprayed in a fan shape under airless spray. A spray is obtained.

Furthermore, when applying the air addition type spray type, the paint is atomized under high pressure as in the airless spray type, and at the same time, the atomizing air is supplied to the air supply path 4.
9 to a cylindrical air nozzle 19 and an auxiliary jet nozzle 20.20.2+ formed around the nozzle 7, which are supplied under an appropriate pressure of usually not more than several J+9/CIIt;
2], 22.22, and added from the outside of the fan-shaped spray that is airless to control atomization and prevent scattering, improve atomization, improve coating efficiency, and improve tail spraying. It is possible to prevent this from occurring, and therefore the paint supply pressure in this case can be significantly lower than in normal airless spraying, and the application of high viscosity paints can be facilitated.

In addition, even when this air addition type spray type is applied, air at an appropriate pressure is supplied from the air supply path 50 in the coating gun 1 as necessary, thereby improving the flattening and widening of the spray. is desirable.

In each of the above spray methods, the degree of paint pressure and air pressure varies depending on various conditions such as the properties of the paint used, viscosity, environmental temperature, and desired coating film conditions. It is important to select the optimal pressure that matches the

〔effect〕

As explained above, the present invention has the following effects.

(a) A painting gun compatible with airless spraying, air spraying, and air-additional spraying is adopted, and paint and air can be supplied to this painting gun under pressure suitable for each spray. This allows one paint gun to be used for various types of spraying, and is therefore suitable for intermediate coating of thick film coatings.

It can be easily applied to any type of coating, including metallic coating, top coating, and finishing coating.

(b) Since a common painting gun can be used and various equipment such as paint supply and air supply can be partially shared, equipment costs and occupied space can be significantly reduced.

(C) Regarding coating film formation during each painting process, when the same paint is sprayed multiple times, it is possible to easily make changes such as introducing a thick coating using airless spray in the initial spraying of the multiple sprays. It is possible to improve coating efficiency.

(d) Type of paint if a color changing device is used to switch between nine paint types.

Even if it becomes necessary to change one spray system due to a change in color, this can be easily done by simply changing the supply conditions, etc. using the same equipment such as a painting gun. can.

(e) By adjusting the flow rate of the paint, the thickness of the paint film can be adjusted, and uniform coating can be easily achieved by controlling the thickness of the paint film0 (f) When supplying the paint Since we installed a paint pump adapted to low-pressure supply and a 7゛-meta pump adapted to high-pressure supply, we adjusted the pressure with the low-pressure paint pump since it was difficult to adjust the pressure at low pressure with the high-pressure pump. In addition, by providing separate flow control valves for low pressure and high pressure and switching between them, the equipment can be used stably over a long period of time, and with high precision. The flow rate can be adjusted to

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIGS. 1 and 2 are a vertical side view and a front view showing the head of a painting gun, respectively, and FIG. 3 is a line taken along the line ■-■ in FIG. 4 and 5 are respectively a vertical sectional side view and a back view of the paint nozzle, and FIG. 6 is a cross-sectional plan view taken along the line M-M in FIG. 4.
7 and 8 are longitudinal sectional side views and rear views of different paint nozzles, respectively, and FIG.
A cross-sectional plan view taken along the line IK-■ in the figure, and FIG. 10 is a system diagram of the coating apparatus. 1 - Paint gun 7... Paint nozzle 19... Cylindrical air nozzle 20 - Auxiliary nozzle port 21 - Auxiliary nozzle port 22... Auxiliary nozzle port 24 - Flat substitute nozzle port 35... Paint pump 36. ・Color change device 37...Booster pump 38 ``'', *tFill adjustment. 1'41...Low pressure flow path 42/Fist 43 ・ 44 ・ 45 ・ 46 ・ 64 ・ High pressure flow path Low pressure flow control valve High pressure flow control valve Flowmeter control device Cleaning device

Claims (1)

[Claims] 1. Adopt a painting gun with a configuration compatible with airless spray, air spray, and air addition type spray, and change the pressure of paint supplied to this painting gun from a low pressure compatible with air spray to airless spray. The pressure can be adjusted to any desired pressure up to the applicable high pressure, and the pressure of the air supplied to the painting gun can also be adjusted to any pressure from about 0 to 10 kg/cm^3, Paint at 20kg/cm without supplying air to the painting gun
The paint is sprayed under high pressure of ^3 or higher, and the paint is applied by airless spray, and the paint applied to the paint gun is several kilograms.
While supplying air under a low pressure of less than g/cm^3, air is supplied to the painting gun under a pressure higher than this paint pressure to perform painting under air spray, and the paint is applied to the painting gun. This is an air addition type in which air is supplied to the painting gun under a relatively high pressure suitable for airless spraying, and air is supplied under a pressure of 10 kg/cm^3 or less, and the air is ejected from the outside of the spray. A painting method that involves applying the paint using a spray. 2. The color changing device selectively supplies a plurality of types of paint to the painting gun, and the paint supply path and the painting gun are cleaned with thinner and air when changing colors. Painting method. 3. The coating method according to claim 1, wherein the paint film thickness is adjusted by controlling the flow rate of the paint using a flow meter, a control device, and a flow control valve. 4. A tailless nozzle is adopted as the orifice type flat paint nozzle (7), a cylindrical air nozzle (19) is formed around this paint nozzle (7), and a spray nozzle for flattening the spray (24) is formed. , (24), and a paint supply device that supplies pressurized paint to the paint gun (1) under any pressure from low pressure suitable for air spray to high pressure suitable for airless spray. and 10 on the paint gun (1)
A device for supplying pressurized air at an arbitrary pressure of kg/cm^3 or less, and a color changing device (36) is attached to the paint supply device so that multiple types of paint can be selectively supplied. In addition to this, the coating equipment is equipped with a booster pump (37) for boosting the pressure. 5. Auxiliary blowholes (20), (20), (21), (
5. The coating apparatus according to claim 4, wherein the cylindrical air nozzle (19) is formed into a tapered conical shape. 6. In order to adjust the paint flow rate, a flow rate adjustment circuit (38) is provided, and this flow rate adjustment circuit (38) is equipped with a flow meter (45), a flow control valve, and a flow rate control valve according to the detection results from the flow meter (45). 5. The coating device according to claim 4, further comprising a regulating control device (46). 7. A paint pump (3) adapted to low pressure supply to the paint supply device.
5) and a booster pump (37) for boosting pressure adapted to high-pressure supply downstream thereof.
5) and (37) that can adjust the supplied paint pressure, and divide the flow rate adjustment circuit (38) into a low pressure flow path (41) and a high pressure flow path (42), and A low pressure flow control valve (43) is installed in the flow paths (41) and (42).
) and a high-pressure flow control valve (44), respectively, are provided separately. 8. The coating method according to claim 1, which is formed by using an electrostatic coating method in combination.