JPH06246201A - Method for cleaning for color changing of multi-color coating apparatus and multi-color coating apparatus using said method - Google Patents

Abstract

PURPOSE:To obtain a method for cleaning for color changing wherein the consumption of a thinner for cleaning can be decreased and high cleaning effect can be kept by feeding a mist cleaning fluid based on the thinner from a mist manufacturing apparatus to a coating color changing apparatus and cleaning the inside and the flow path to a coating machine when cleaning for color changing is performed. CONSTITUTION:When a coating with a certain color is completed, color change valves CV1 to CV7 for the coating color are closed and a cleaning valve 5 of a color changing apparatus 1 is opened and a spraying apparatus 3 is driven by the action of a switch valve 8 to prepare a mist cleaning fluid wherein a cleaning thinner is made into a mist in a cleaning air and the fluid is fed by compression to the cleaning valve 5 and the coating flow path 30 from the color changing apparatus 1 to a coating machine 2 is cleaned and is discharged from the coating machine 2. Then, the cleaning valve 5 is closed and only cleaning air is made to flow from a color change manifold 4 to the coating machine 2 by the action of a switch valve 9 to discharge the remaining thinner from the coating machine 2 and then, after a coating to be used is filled, a trial coating is performed and then, the actual coating is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for changing colors of a multicolor coating apparatus and a multicolor coating apparatus using the method. That is, the present invention is a paint color changing device that selectively supplies paints of several colors to several tens of colors by a color changing operation, and when the color is changed, the paint path from the device to the painting machine is washed. A method of improving the method. INDUSTRIAL APPLICABILITY The present invention is advantageous when performing multicolor coating on automobile bodies or parts.

[0002]

2. Description of the Related Art In an automobile painting factory, in order to perform multi-color painting such as multi-coating with several colors or dozens of colors on an automobile body or the like, the number of color changes corresponding to the number of paint colors is changed. Using a paint color changer with a valve installed, and when changing colors from one paint color to the next, wash the paint path to the painter with thinner and air to eliminate residual paint. is doing. And, in the case of cleaning the paint flow path in this case, conventionally, a method in which the air and the thinner are separately fed alternately from the color changing device to the coating machine several times at intervals of usually several seconds to several tens of seconds is used. Was generally carried out (JP-A-61-46271, etc.).

However, in such a conventional method, the air and the thinner flow in the paint path separately and hardly in admixture, so that a sufficiently high cleaning effect cannot be obtained, and sometimes before the color change. In some cases, the residual paint of (1) was discharged from the coating machine in the subsequent coating.

As one method of solving this problem, the applicant of the present invention, as disclosed in Japanese Patent Laid-Open No. 2-261565, connects the mixing assembly to a color changing device, and in the case of color change cleaning, in the mixing assembly, Low pressure cleaning air is blown into the flow of the low pressure cleaning thinner to create an air / thinner mixture in which air bubbles are mixed in the thinner, and this mixture is supplied to the color changing device to the coating machine. I proposed the technical means of washing the.

Even after that, the present applicant has proposed a few technical means for improving the mixed state of air and thinner in order to further enhance the effect of color change cleaning (Japanese Patent Application No. 3-126820). , Japanese Patent Application No. 3-126819, etc.).

[0006]

However, the above-mentioned air
The thinner liquid mixture generally has a flow ratio of air to thinner in the range of 1: 1 to 1:10, usually 1: about 1-2, so that the flow of the liquid mixture will make the paint route to the coating machine. The cleaning method has the disadvantage that the amount of cleaning thinner used is still considerably high.

Due to the recent circumstances in which environmental pollution has been taken into account and the prevention of the diffusion of pollutants is required, it is desired to suppress not only the amount of paint but also the amount of thinner as much as possible even in an automobile painting factory. There is. However, the above-mentioned color change cleaning method has not been able to sufficiently meet such a request.

In addition, the cleaning method using an air / thinner mixed solution generally makes it difficult to form a fluid in which air and thinner are sufficiently homogeneously mixed, unless the improved technical means proposed by the applicant is adopted. However, there is also a drawback that it is difficult to obtain a desired high cleaning effect.

Therefore, the object of the present invention is to compare with a cleaning method using an air / thinner mixture,
The amount of thinner used for cleaning can be further reduced,
And, at least, it is to provide a color changing cleaning method for a multicolor coating apparatus capable of maintaining the same high cleaning effect as in the case of using an air / thinner mixed liquid. Also,
Another object of the present invention is to provide a multicolor coating apparatus used for carrying out such a color changing cleaning method.

[0010]

Means for Solving the Problems The present inventor revised the conventional idea that air bubbles are dispersed in a thinner to prepare a mixed liquid of the two, and fine droplets of the thinner are dispersed in the air so that the air-based A new idea of making a fluid of the above was conceived, and based on the idea, a general-purpose spray mixer was connected to a paint color changing device, and in the mixer, a cleaning thinner was atomized in the cleaning air, and the resulting atomized cleaning fluid was generated. Unexpectedly, even if the atomized cleaning fluid is used, the paint flow path from the color changer to the coating machine can be cleaned very effectively when Moreover, they have found that it is not necessary to significantly increase the total amount of cleaning fluid used, and completed the present invention.

That is, according to the present invention, when the color change cleaning is performed by the atomizing cleaning fluid in which the cleaning thinner is atomized in the cleaning air, the flow path from the paint color changing device to the coating machine is cleaned,・ High cleaning effect when using thinner mixed fluid is kept to a minimum, and consumption of cleaning thinner is greatly reduced.

[0012] Therefore, the color change cleaning method for the multicolor coating apparatus according to the present invention is a multicolor coating apparatus in which an atomizing apparatus for atomizing a cleaning thinner in a flow of cleaning air to produce an atomized cleaning fluid is provided. It is connected to a paint color changing device that communicates with a painting machine, and at the time of color changing cleaning, the atomization cleaning fluid is fed from the atomizing device to the paint color changing device, and inside the paint color changing device and the painting machine It is characterized in that the channels up to are washed.

Accordingly, the present invention is a coating apparatus for using such a color changing cleaning method, which comprises a coating machine, a paint color changing apparatus in communication with the coating machine, and a connection to the paint color changing apparatus,
The present invention also relates to a multicolor coating device including an atomizing device that atomizes a cleaning thinner in a flow of cleaning air to form an atomized cleaning fluid at the time of color changing cleaning, and feeds the atomized cleaning fluid to the paint color changing device. .

(Outline of the Invention) The multicolor coating apparatus used in the color changing and cleaning method of the present invention has a conventional structure, that is, in addition to a coating machine and a paint color changing apparatus in communication therewith, an atomizing apparatus is used for the paint color. It is connected to the replacement device. The atomizing device may be any device as long as it is a device that atomizes the cleaning thinner in the flow of the cleaning air to create an atomized cleaning fluid during the color change cleaning and feeds this to the paint color changing device. , The model, etc. does not matter at all. For example, a general-purpose spray mixer or the like can be used for the atomizing device.

In the color change cleaning process according to the method of the present invention, when the color change cleaning of a certain color is performed, the paint flow path to the coating machine is completely cleaned by the atomizing cleaning fluid, and then the extrusion air (thinner or the like is mixed therein). Is preferably sent to the paint flow path for a certain period of time, the atomized cleaning fluid remaining in the paint flow path is sent out, and then the trial coating of the paint of the next color is performed.

[0016]

Since the cleaning method of the present invention uses the atomized cleaning fluid in which the thinner is atomized as the cleaning fluid in the color changing cleaning, the thinner flow rate and the air flow rate used for cleaning are The ratio depends on the size of the thinner fog,
Approximately 1: about 100 to 1: about 1000, usually 1:
It will be about 300-600. On the other hand, the total flow rate of the cleaning fluid used for color change cleaning may increase one to several times as compared with the case of using the air / thinner mixed solution in order to achieve a satisfactory cleaning action. 10 times,
It is not necessary to increase the flow rate used up to 100 times. Therefore, the total amount of the cleaning thinner used in the color change cleaning is reduced to a fraction to a few tenths as compared with the case of the air-thinner mixed liquid.

Furthermore, the atomized cleaning fluid used in the present invention, which is a thinner atomizer, easily dissolves the residual paint in the paint passage and exhibits a very high cleaning action. this is,
It is considered that fine thinner fog droplets uniformly spread throughout the paint channel, particularly in the fine details, and come into contact with all the paint particles in the channel. On the other hand, when an air-thinner mixture is used, it may occur that the paint particles come into contact with air bubbles having a relatively large cross-sectional area during cleaning and remain undissolved in the thinner solution. Ah Therefore, the cleaning method according to the present invention can exhibit a cleaning action equivalent to or higher than that in the case of using the air-thinner mixed liquid.

Of course, the cleaning method according to the present invention has a significantly increased cleaning action as compared with the conventional cleaning method in which air and thinner are separately sent alternately, so that the total time required for color change cleaning is reduced. This enables shortening. Moreover, since it is not necessary to frequently operate the air supply valve and the thinner supply valve, the durability of the multicolor coating device is remarkably improved.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a multicolor coating apparatus used in the color change cleaning method of the embodiment. This device comprises a paint color changing device 1, a coating machine 2 and an atomizing device 3. The paint color changing device 1
It is arranged near the coating machine 2 and communicates with the coating machine 2 via a metering valve 10. The color changing device 1 supplies _seven color change valves CV _{1 to} CV 7 corresponding to the paint color (white, light yellow, gray, etc.) to be used to the side of the color changing manifold 4 and pushing air. The extruding air valve 6 is assembled, and the atomizing device 3 is attached to the base end thereof.
The cleaning valve 5 is connected to the cleaning valve 5. There is no particular limitation on the number of color change valves to be assembled in the paint color changing device and their installation positions. However, when the number of paint colors is very large, in general, it corresponds to the paint colors that are used less frequently. A method of connecting another paint color changing device, in which a color changing valve or the like is assembled, to the color changing manifold 4 via a trigger valve is adopted.

The atomizing device 3 is a spray mixer connected to the cleaning valve 5 of the color changing device 1 by a hose 13,
The thinner liquid can be atomized in a stream of air to produce an atomized cleaning fluid. The atomizing device 3 is connected to the cleaning thinner source 11 and the cleaning air source 12 via the pressure adjusting valve 7 and the check valve 14, respectively, and is operated by the on / off operation of the switching valve 8. There is. The switching valve 8 is also connected to the cleaning valve 5 of the color changing device 1 so that the cleaning valve 5 can be operated simultaneously with the atomizing device 3.

The extruding air valve 6 of the color changing device 1
Is connected to a cleaning / cleaning air source 12 via a pressure adjusting valve 7 and is operated by turning on / off the switching valve 9.

FIG. 2 shows the details of the atomizing device 3. This device 3 is constructed by assembling the mixer 15 on the opposite side of the manifold 16 connecting the hose 13 so as to communicate with the hose 13 via a connecting cylinder 17. The mixer 15 has a double structure in which a thinner cylinder 18 is housed, and a thinner chamber 19 inside the cylinder 18 communicates with the cleaning thinner source 11, while an air chamber 20 outside the cylinder 18 It is connected to the cleaning air source 12. Each of the thinner chamber 19 and the air chamber 20 has a nozzle portion 21 formed on the mixer base side (manifold 16 side) and communicates with the spray chamber 22 in the connecting cylinder 17. Further, the mixer 15 is configured such that the needle valve 23 is accommodated in the longitudinal direction along the center line thereof from the cylinder chamber 24 on the tip side of the mixer to the air chamber 20 and the thinner chamber 19. The spring 25 is interposed between the inner wall of the cylinder chamber 24 and the core 26 of the needle valve 23, and the needle valve 23 moves forward and backward toward the hole of the nozzle portion 21 by pressurizing and releasing the pilot air. Is made like. Pressurization of pilot air and its release are performed by the switching valve 8 described above. 27 is pilot air pressure and spring 25
The screw for adjusting with the biasing force of is shown. Further, a truncated cone-shaped valve 28 is attached to the central portion of the needle valve 23, and a rim-shaped valve seat 29 is formed on the inner wall of the air chamber 20. By abutting against or separating from the seat 29, it is possible to stop and release the introduction of air into the air chamber 20 (spray chamber 22). Further, the tip portion 31 of the needle valve 23 is formed in a taper shape, and the inner wall 32 of the thinner cylinder 18 on the nozzle portion side has a shape corresponding to the taper shape. Three
By bringing 1 into contact with the inner wall 32 or separating from it, it is possible to stop and release the introduction of thinner into the spray chamber 22. And the tip portion 31 in this case
The valve 28 and the valve seat 29 are brought into contact with each other and separated from the inner wall 32.
It is designed to be performed at the same timing as the contact and separation with and.

Therefore, the needle valve 23 is the switching valve 8
It is designed to be opened and closed by advancing and retreating by the on / off operation of, and when opened, cleaning air and cleaning thinner are simultaneously ejected through the nozzle portion 21 into the spray chamber 22 of the connecting cylinder 17. By being supplied,
It becomes atomized and the atomized cleaning fluid A is generated.

Thus, in this embodiment, color change cleaning is performed according to the following procedure. As shown in FIG. 1, when a paint of a certain color is completed, immediately, a color change valve (CV ₁ to CV ₇ of that paint color,
Other valves are already closed because they are not in use. ) Is closed, and then the cleaning valve 5 of the color changing device 1 is opened, and at the same time, the atomizing device 3 is operated by the operation of the switching valve 8 to atomize the cleaning thinner in the cleaning air. And send it under pressure to the cleaning valve 5,
The paint flow path 30 from the color changing device 1 to the coating machine 2 is washed and discharged from the coating machine 2. After the cleaning with the atomized cleaning fluid A is completed, the cleaning valve 5 is closed and at the same time,
The extruding air valve 6 is opened for 1 to 2 seconds by the operation of the switching valve 9, and only the cleaning air is changed in color.
To the coating machine 2 are made to flow through the coating material flow path 30, and the thinner residue remaining in the flow path 30 is discharged from the coating machine 2. After that, after filling the paint of the color to be used next, trial painting is performed for an appropriate time, and the main painting is started.

In the embodiment, when the color of the paint is changed, the fine paint droplets from the color changing device to the coating machine are washed with the atomized cleaning fluid in which the thinner fine droplets are uniformly dispersed in the air in the form of a mist. It was possible to obtain a very high cleaning effect reliably and stably. Moreover, the amount of thinner used could be significantly reduced as compared with the case of using the air-thinner mixed fluid.

[0027]

As described above, according to the present invention,
The total amount of cleaning thinner used for cleaning the path to the coating machine during color change is reduced to a fraction to a few tenths compared to the case of using an air-thinner mixture, for example. Therefore, it is possible to contribute to the reduction of the thinner consumption in the automobile painting, and further to the prevention of environmental pollution.

Furthermore, according to the present invention, a very high cleaning effect can be exhibited in the color change cleaning, and at least the same effect as when using the air-thinner mixed liquid can be maintained.

[Brief description of drawings]

FIG. 1 is a diagram showing a multicolor coating apparatus used in a method according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the inside of an atomizing device of the multicolor coating device of the embodiment.

[Explanation of symbols]

1 paint color changing device 2 coating machine 3 atomizing device 4 color changing manifold 5 cleaning valve 6 extrusion air valve 11 cleaning thinner source 12 cleaning air source 30 paint flow channel CV _{1 to} CV ₇ color change valve A atomization cleaning fluid

Claims (2)

[Claims] 1. In a multicolor coating device, an atomizing device for atomizing a cleaning thinner in a flow of cleaning air to produce an atomized cleaning fluid is connected to a paint color changing device in communication with a coating machine, At the time of replacement cleaning, the atomizing cleaning fluid is fed from the atomizing device to the paint color changing device to clean the inside of the paint color changing device and the flow path from this to the coating machine. How to change color of coating equipment. 2. A coating machine, a paint color changing device which communicates with the coating machine, and a paint color changing device which is connected to the paint color changing device and atomizes the cleaning thinner in the flow of cleaning air during color change cleaning. A multicolor coating device comprising atomization means for producing an atomization cleaning fluid and feeding the fluid to the paint color changing device.