JPH09201555A - Coating apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make piping smaller, simpler, and less expensive in costs. SOLUTION: A mixer 11 is installed in the passage 10 between a coating gun 1 and a color changing valve 2. Coating stored in coating storage sources 3A, 3B, etc., which are connected with the valve 2 is left undiluted. A solvent changing valve 22 is connected with the mixer 11 through a passage 25 in parallel with the valve 2. Solvent storage sources 21A, 21B, etc., are connected with the valve 22. The undiluted coating supplied through the valve 2 and a solvent supplied through the valve 22 are mixed adequately by the mixer 11, and the mixture is discharged from the coating gun 1. A return passage for constituting a coating circulating circuit and a mixer for preventing the separation of coating are not formed between the valve 2 and the storage sources 3A, 3B.

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 automobile bodies and the like.

[0002]

2. Description of the Related Art In a coating apparatus, an arbitrary one of a plurality of types of coating colors prepared in advance is selected and supplied to a coating gun, as seen in, for example, coating on an automobile body. Therefore, a color changing valve is often used (see, for example, Japanese Utility Model Laid-Open No. 3-86067). A solvent (thinner) for cleaning can be supplied to the color changing valve, and when changing from one coating color to another coating color, the solvent is applied to the system path from the color changing valve to the coating gun. It is supposed to be washed by.

The paint to be supplied to the color changing valve is prepared in advance by mixing a solvent with respect to the paint stock solution in a predetermined ratio, and the mixture solution of the paint stock solution and the solvent is supplied in a paint supply source in advance. It is stored in (paint tank). In this way, in the mixed solution in which the undiluted coating solution and the solvent are preliminarily mixed, those having a large specific gravity such as metallic material (aluminum powder or mica powder) are precipitated, and those having a small specific gravity such as solvent are the supernatant liquid. It is easy to separate as.

For this reason, conventionally, a liquid supply system for supplying the mixed liquid toward the color changing valve between the mixed liquid storage source storing the mixed liquid of the paint and the solvent and the color changing valve. In addition to the path, the return path, that is, the return path
By connecting the mixed liquid through the flow path, the mixed liquid as a whole circulates through the color changing valve to form a circulation system, and a mixer (stirrer) for stirring the mixed liquid is provided in the circulation line. ).

[0005]

However, in the above-mentioned conventional coating apparatus, the color changing valve must be provided with the return system passage and the mixer for each paint storage source. There is a problem that the piping becomes large-scale and the cost becomes high. In particular, since the paint storage source and the color changing valve are often installed at a great distance from each other and the return system path becomes considerably long, the above-mentioned problem becomes remarkable.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a coating apparatus and a coating method capable of reducing the size of the apparatus as a whole and reducing the installation cost.

[0007]

In order to achieve the above-mentioned object, in the present invention, basically, a coating solution which is stable in properties and does not separate from a coating solution passing through a color changing valve is prepared. As it is, the solvent is supplied to the undiluted coating solution after passing through the color changing valve and before reaching the coating gun.

Specifically, in the coating apparatus according to the present invention, the first configuration is as follows. That is, in a coating apparatus in which the coating supply means for supplying coating to the coating gun has a color changing valve,
The paint supplied to the coating gun side through the color changing valve is used as a stock solution, and a solvent supply means is connected to a system path between the coating gun and the color changing valve. It is as a configuration.

Further, in the coating apparatus according to the present invention,
The second configuration is as follows. That is,
Multiple storage sources, each storing a stock solution of paint, are connected,
A color changing valve for selecting any one of the stock solutions of the storage sources, and the color changing valve.
A mixing means connected to the system between the changing valve and the coating gun, and a system connected to the system path between the color changing valve and the coating gun for supplying the solvent through the mixing means. And a solvent supply means of.

Further, the coating method according to the present invention has the following structure. That is, the coating stock solution is supplied to the coating gun through the color changing valve, and the coating stock solution from the color changing valve is supplied to the coating stock solution before the coating stock solution from the color changing valve reaches the coating gun. The composition is such that the solvent is mixed with it.

[0011]

According to the invention described in claim 1, since the paint supplied to the color changing valve remains as the paint undiluted liquid having stable properties, each paint undiluted liquid is separated to prevent the paint from separating. It is not necessary to separately provide a return system passage and a mixer, so that piping can be simplified and cost can be reduced. Further, since it is stored as it is as a coating stock solution having stable properties, it is also preferable for improving storage stability. Furthermore, it becomes easy to appropriately change the dilution ratio with the solvent while using the same coating solution. In addition to the above, it is not necessary to operate the mixer to prevent the separation of the coating stock solution that is not used, that is, the coating stock solution that is not selected by the color changing valve, so that it is also preferable in reducing the running cost. Become.

With the structure as described in claim 2, the undiluted coating solution and the solvent are sufficiently mixed by the mixing means before reaching the coating gun, and the dilution ratio of the coating material discharged from the coating gun is adjusted. This is preferable for surely preventing the situation of fluctuation.

With the configuration as described in claim 3, the dilution ratio can be easily changed by changing the solvent supply amount.

With the structure as described in claim 4, it is possible to easily select an appropriate solvent according to the type of the coating solution.

With the structure as described in claim 5, it is possible to discharge from the coating gun a paint having a preferable dilution ratio corresponding to the inner plate and the outer plate of the automobile body.

According to the invention described in claim 6, it is possible to obtain the same effect as that of claim 1.

By adopting the structure as described in claim 7, it is clarified that the structure does not have the return system passage and the mixer which are conventionally installed for each paint storage source. Will be provided.

According to the invention described in claim 8, the effect corresponding to claim 1 can be obtained.

With the construction as described in claim 9, it is possible to make the dilution or the dilution ratio of the paint discharged from the coating gun appropriate.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION In FIG. 1 showing a first embodiment of the present invention, 1 is a coating gun and 2 is a color changing valve. The color changing valve 2 is connected to a plurality of storage sources each storing a stock solution of paint, but in FIG. 1, only two storage sources 3A and 3B are shown, and other storage sources are not shown. There is. The storage source 3
The later-described constituent elements provided corresponding to A and 3B are similarly provided for other storage sources (not shown) (this also applies to the solvent storage source described later). Further, the coating material stock solution stored in each of the storage sources 3A, 3B and the like remains as delivered from the coating material manufacturer and is not diluted with a solvent thereafter.

The respective storage sources 3A, 3B and the color changing valve 2 are connected to each other via the stock solution supply systems 4A, 4B. In each supply system path 4A, 4B,
Pumps 5A and 5B for individually supplying the stock solutions of the reservoirs 3A and 3B to the color changing valve 2 are connected to each other. The pumps 5A and 5B are metering pumps and have the same rotation speed. The one that ejects the same amount is used.

Painting gun 1 and color changing valve 2
Are connected to each other by a system path 10, and a mixer (stirrer) 11 is connected to the system path 10. This mixer 11 is for uniformly mixing the solvent with the coating stock solution from the color changing valve 2. In the embodiment, a static mixer is used.
Each of the above-mentioned components 2, 3A, 3B, 4A, 4B, 5
A portion 5A upstream of the mixer 11 in A, 5B, and the system passage 10 constitutes a coating material undiluted solution supply means T1 for supplying the undiluted material solution to the mixer 10. The color changing valve 2 has a color changing valve when changing colors.
A cleaning solvent for cleaning the downstream side of the changing valve 2 can be supplied. As a component related to this cleaning solvent, the cleaning solvent storage source is designated by reference numeral 6, and the cleaning solvent supply system is designated by reference numeral. At 7, the pump is shown at 8.

A solvent supply means T2 is connected to the mixer 11. The solvent supply means T2 is provided in parallel with the coating material undiluted solution supply means T1 and has a plurality of solvent storage sources that store different kinds of solvents (for example, different kinds of organic solvents). In FIG. Reservoir sources 21A and 21
Only B is shown and other solvent reservoirs are not shown. Further, the solvent supply means T2 has a solvent changing valve 22. The solvent changing valve 22 and each of the solvent storage sources 21A and 21B are independently connected by system paths 23A and 23B, and pumps 24A and 24B are connected to the system paths 23A and 23B.

The solvent changing valve 2 has the same structure as the color changing valve 2 (the color changing valve 2 is diverted). Also, pumps 24A, 24
B is a metering pump that discharges the same amount at the same rotation speed.

The solvent changing valve 22 and the mixer 11 are connected by a system path 25. As a result, the paint stock solution after passing through the color changing valve 2 and the solvent after passing through the solvent changing valve 22 are sufficiently mixed by the mixer 11.

The paint stock solution is colored between the color changing valve 2 and the stock stock solution storage sources 3A, 3B.
There is no return system path for returning from the changing valve 2 side to the storage sources 3A, 3B side, or a mixer for mixing the diluting solvent and the coating solution.

Next, the operation of the above configuration will be described. First, for example, consider a case where coating is performed by using the coating stock solution of the coating stock solution storage source 3A. At this time, only the pump 5A corresponding to the storage source 3A is operated, and the pumps 5B for the other raw material stock solution storage source 3B and the like are stopped. Also, the color
The changing valve 2 is a selection of the stock stock solution storage source 3A,
That is, the system path 10 (10A) leading to the coating gun 1 is connected to the storage source 3
A selection is made to connect only to the path 4A corresponding to A. As a result, the undiluted paint solution from the undiluted paint solution storage source 3A is supplied to the mixer 11 via the color changing valve 2.

On the other hand, in the solvent supply means T2, a storage source for storing the solvent corresponding to the coating stock solution storage source 3A, for example, the solvent storage source 21A is selected. More specifically, only the pump 24A corresponding to the solvent storage source 21A is operated, the other pumps 24B and the like are stopped, and the solvent changing valve 22 causes the system path 25 to correspond to the solvent storage source 21A. Connect to 23A only. As a result, the solvent stored in the solvent storage source 21A is supplied to the mixer 11 via the solvent changing valve 22.

The mixer 11 supplied with the coating stock solution and the solvent as described above sufficiently mixes the coating stock solution and the solvent to obtain a mixed solution in which the coating stock solution is uniformly diluted with the solvent. Then, the mixed liquid that has passed through the mixer 11 is discharged from the coating gun 1. Of course, the dilution ratio of the coating stock solution with the solvent depends on the number of rotations of the pumps 5A and 24A.

To change the dilution ratio of the coating stock solution with the solvent, at least one of changing the solvent supply amount (changing the rotation speed of the pump 24A) or changing the coating stock solution supply amount (changing the rotation speed of the pump 5A) is performed. be able to. In addition, the running cost can be reduced by suspending the pump corresponding to the undiluted coating solution and solvent. In addition, at the time of color change, the system path 10 (10A) is changed to the system path 8 of the cleaning solvent by the color changing valve 2.
And the pump 8 is operated to wash the inside of the system passage from the color changing valve 2 to the coating gun 1 with the washing solvent.

FIG. 2 shows a second embodiment of the present invention.
The same components as those of the above-described embodiment are designated by the same reference numerals, and the duplicated description will be omitted. In this embodiment, there is only one solvent for dilution. For this reason, the solvent changing valve 22 is not provided, and the system paths 23A and 25
And are the same route.

In this embodiment, the pump 24A is variably controlled by the control unit U as a control means in order to change the supply amount of the diluent solvent. Therefore, the control unit U receives a signal from the temperature sensor S1 as a temperature detecting means for detecting the outside air temperature (temperatures of the stock solutions of the raw material coating liquids 3A, 3B, ...). Then, when the outside air temperature is high (the viscosity of the coating solution is small), the supply amount of the diluent solvent is reduced as compared to when the outside air temperature is low (the viscosity of the coating solution is large).

Another example of changing the supply amount of the solvent for dilution may be as follows. First, change according to the difference of the surface to be coated, for example, when painting a car body,
The solvent supply amount can be changed between the inner plate and the outer plate. More specifically, in the case of inner plate coating, where the appearance (finish of the coated surface) does not matter so much, the solvent supply amount is reduced (small dilution ratio of the coating solution) to shorten the coating time, In the case of outer panel coating where appearance is a problem, the solvent supply amount is increased (dilution ratio of the coating solution is the second highest) in comparison with the case of inner panel coating to obtain a good coated surface.

Although the embodiment has been described above, the present invention is not limited to this, and the following may be adopted, for example. The supply amount of the diluting solvent can be changed according to the type of the coating solution (color difference, difference between solid system and metallic system, etc.) or the supply pressure of the coating solution. Further, the type of the diluting solvent can be changed according to the type of the coating solution (color difference, difference between solid type and metallic type, etc.).

The diluting solvent is not supplied to the mixer 11 directly, but at a position passing through the mixer 11, for example, an appropriate position such as an intermediate position between the mixer 11 and the color changing valve 2 is selected. it can.

The object of the present invention implicitly includes not only the specified one but also the one corresponding to the contents described as preferable or advantageous.

[Brief description of drawings]

FIG. 1 is an overall system diagram showing one embodiment of the present invention.

FIG. 2 is an overall system diagram showing another embodiment of the present invention.

[Explanation of symbols]

1: Coating gun 2: Color changing valve 3A, 3B: Paint stock solution storage source 5A, 5B: Paint stock solution supply pump 10: Connection line between paint gun and color changing valve 11: Mixer 21A, 21B : Diluting solvent storage source 22: Solvent changing valve 24A, 24B: Diluting solvent supply pump T1: Paint stock solution supply means T2: Solvent supply means

Claims (9)

[Claims] 1. A coating apparatus having a color changing valve as a coating supply means for supplying a coating gun with a color changing valve, wherein the coating material supplied to the coating gun side through the color changing valve is a coating stock solution. A coating device, wherein a solvent supply means is connected to a system path between the coating gun and the color changing valve. 2. A mixing means is connected to a system path between the coating gun and the color changing valve, and the solvent from the solvent supplying means is set to pass through the mixing means. And a coating stock solution from the color changing valve and a solvent from the solvent supply means are mixed by the mixing means and then supplied to the coating gun. . 3. The coating apparatus according to claim 1 or 2, wherein the solvent supply means is set so that a solvent supply amount can be changed. 4. The solvent supply means according to claim 2 or 3, wherein the solvent supply means has a solvent changing valve and can selectively supply one kind of solvent to the mixing means from a plurality of kinds of solvents. Set according to the type of the coating solution to be supplied from the color changing valve toward the mixing means by the solvent changing valve, the solvent supplied from the solvent changing valve toward the mixing means A coating device characterized in that the type is set to be selected. 5. The coating device according to claim 3, wherein the coating device is for coating an automobile body, and the solvent supply amount is changed depending on whether the inner plate of the automobile body is coated or the outer plate is coated. Has been
A coating device characterized in that 6. A color changing valve, which is connected to a plurality of storage sources each storing a coating stock solution, for selecting any one coating stock solution from the coating stock solutions of the respective storage sources, and the color changing valve. And a mixing means connected to the system between the coating gun and the coating gun, and a solvent connected to the system between the color changing valve and the coating gun for supplying a solvent so as to pass through the mixing means. A supply device, and a coating device. 7. The color changing valve according to any one of claims 1 to 6, wherein the color changing valve is provided between the color changing valve and a storage source of a raw material coating solution supplied to the color changing valve. A coating device, characterized in that it does not have a return line for returning the coating solution from the side and a mixing means with a solvent. 8. A coating solution is supplied to a coating gun through a color changing valve, and before the coating solution from the color changing valve reaches the coating gun, the coating solution is supplied from the color changing valve. A coating method characterized by mixing a solvent with an undiluted solution. 9. The method according to claim 8, wherein at least one of the type and amount of the solvent mixed with the coating stock solution is changed according to the change of the coating stock solution or the type of the coated surface. Characteristic coating method.