JPS6031554B2 - Coating method and equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for selecting and applying a specified color of paint.

In the spray painting process, for example, in the top coating process of automobiles, the terminals of multiple paint supply circuits are conventionally connected to a color changer to select one paint, which is then supplied to the auto spray gun of the reciprocator. Automated spray painting is carried out by selecting a specified color for each car body that is continuously conveyed by a conveyor, but in order to prevent color mixing when changing colors, a special device is attached to the color changer. We perform solvent cleaning and air blow cleaning of paint circuits such as spray guns and the pipes that connect them. However, when a large number of colors are used, such as in the top coating process of automobiles, the color changer is inevitably large, so it is not possible to attach it to the reciprocator's drive element; A changer is fixed outside the reciprocator body, and the paint selected by the changer is supplied via a long flexible pipe to an auto spray gun connected to the driver. Therefore, a problem arises in that cleaning the pipe line requires a large amount of solvent and a large amount of time. Furthermore, when performing powder coating, cleaning is performed using a high-pressure blower when changing colors, but since it is difficult to completely clean powder coatings, this is especially true for long flexible pipes as mentioned above. However, it is difficult to use a color changer because a relatively large amount of paint remains, which causes problems such as mixing with new paint and causing color mixing. In view of the above points,
SUMMARY OF THE INVENTION An object of the present invention is to provide a method and apparatus for reliably painting by preventing harmful color mixing of paints during a color changer.

Next, the present invention will be explained with reference to the drawings, taking a powder topcoating device as an example.

Figure 1 is a system diagram of the main parts of the top coat powder coating equipment that allows la weight selection, and IA, IB, IC, and ID are for top coat powder coatings of colors A, B, C, and D, respectively. This is a supply device, and powder paints of respective colors are supplied to hoppers 2A, 2B, 2C, and 2D of the device through paint supply pipes 3A, 3B, 3C, and
It is sent from 3D via cyclones 4A, 4B, 4C, 4D or a bag filter not shown. 5A is an air pipe that branches from the main air supply pipe R and reaches the air nozzle of the venturi mechanism 5 of the hopper 2A, and this air pipe includes a regulator RA and a solenoid type whose opening and closing are controlled by a control panel (not shown). The air switching valve V is regularly installed.

Note that when the air switching valve V is open, the air for pumping the powder paint reduced to a predetermined pressure by the regulator RA reaches the air nozzle of the venturi mechanism 5, and the powder paint in the hopper is transferred to the air nozzle as described below. Force feed to auto spray gun 50. Next, the present invention will be explained in more detail using A-color powder coating as an example.

That is, the powder paint reaches the lower part of the hopper while flowing and mixing with air in the hopper 2A, and the required amount is supplied to the color changer 70 A by the Venturi mechanism 5 via the powder paint supply pipe 6A. This leads to color change valve means 7A. This configuration is the same for colors B, C, D, etc., so the explanation will be omitted. Here, A color, B
Among the powder paints with a total of la colors of color, C color, ...... L color, paint A color has little effect on the finished color of the object to be coated even if it is allowed within the limit of mud color, One group includes B, C, and D colors, such as white and silver gray, and one group includes E, F, G, and H colors, such as red and black. Furthermore, one color, J color, K color, L color, for example, violet and green paint colors, is set as one group, and powder coatings belonging to each group are provided corresponding to each group. 1st stage color changer 70, 80, 9 supply pipes for each color of paint 6A, 6B, 6C, 6D; 68,
6F, 6H; 61, 6J, 6K, 6L. Color changers 70, 80, and 9 have the same structure, so to explain in detail, color changers 7A, 7B, 7C, 7D, and 7M are the sum of colors A, B, C, and C. Suction openings □ connected to supply pipes 6A, 6B, 6C, 6D, and 6M dedicated to the four colors of powder paint and high-pressure washing air, and pinch-type pipes that communicate with the suction openings □, respectively.

The valve means is a valve means that incorporates a switching valve such as a needle-type switching valve, a discharge hole of the switching valve, and a means for opening and closing the switching valve, such as an air cylinder device, and the valve means is integrally combined.
The discharge holes are configured to communicate with one paint supply pipe through a common collecting hole. The paint supply pipe 10 is connected to a first valve means 1 of a second stage color changer 100, which will be described later.
Transported to 01. Next, the control air circuit 8 of the color changer 70 includes a branch pipe 81 from the main air supply pipe R, a filter F/air regulator RS and an oiler 1 which are successively installed in the branch pipe 81, and the ridge oiler. The color changer 7 is further branched from the branch pipe 81 downstream from the color changer 7.
Pipe lines 8A, 8B, 8C, 8D, 8M that communicate with each of the air cylinder devices built in each valve means of 0;
Normally closed solenoid valves SA, SB, S installed in the pipe line
For example, when a command signal for A color painting is sent from a control panel (not shown), only the solenoid valve SA is opened or closed by the command signal, and the air regulator RS is used to maintain a predetermined pressure. The reduced pressure flows into the air cylinder device of the valve means 7A and drives the air cylinder device, causing the switching valve of the valve means 7A to engage.
Only the powder paint of color A is supplied to the valve means 101 via the paint supply pipe 10.

Reference numerals 20 and 30 are paint supply pipes extending from the collecting holes of the color changers 80 and 90 to the second valve means 102 and third valve means 103 of the second stage color changer 100, respectively, and as described later, When the two-stage color changer 100 moves, the paint supply pipes 10, 20, 30
, is composed of flexible tubes.

40' is a paint supply pipe that communicates between the collection hole of the color changer 100 and the paint introduction port of the auto spray gun 50 for powder electrostatic coating.

The auto spray gun 501 is connected to a high voltage cable 51 for applying a high voltage from a high voltage generator controlled by the control panel to the electrodes of the gun 50 and a conduit 52 for supplying pattern air. Air that has been purified by an air transformer and has a predetermined pressure is supplied to this pipe line 52, and this air is controlled by opening and closing of a solenoid valve Sp installed in the pipe line 52 in synchronization with the powder paint discharge. The spray gun 50' is supplied as pattern air. When attaching the auto spray gun 50 to the reciprocating locator, the second stage color changer 100 is disposed above the auto spray gun, the paint supply pipe 40 is disposed vertically, and these are integrated. For example, it is preferable to fasten it to the drive element 105 of the reciprocator.

In addition, the coating apparatus according to the above-mentioned configuration is one in which one auto spray gun is arranged in a color changer system that can select from 123 powder coatings, and each color changer 70, 80, By reducing the number of valve means (90,100), for example, by dividing the powder coatings of six colors into three groups as described above, and by dividing the powder coatings of six colors into three groups as described above, powder coatings with coating colors selected by the same method as described above can be obtained. It is clear that it is possible to paint 12 colors by installing two such devices in parallel and installing two auto spray guns in parallel with a top reciprocator with an appropriate distance between them. It is also possible to select and apply powder paint.

Furthermore, it is clear that a similar arrangement of color changers can be used for solvent-based top coat paints and the like. The color changer 701 has been described in detail above, but since the color changers 80 and 90 have a similar configuration, their description will be omitted in this specification to avoid duplication.

Next, the operation of the powder coating device based on the above-mentioned configuration,
Regarding the painting method, Fig. 1 shows an example of changing the color from A color, for example, white to E color, e.g., red, and Fig. 2 is an explanatory diagram of the color change program.
This will be explained with reference to the figures.

For example, when a control panel with a built-in sequence circuit is operated to change the color from color A (white) to color E (red), the paint valve built in the venturi mechanism 5 of the powder paint supply device IA closes first. Then, the color A painting is completed using the remaining paint in each tube path from the supply pipe 6A for the color A paint to the auto spray gun 50 and in each valve means, and then the air switching valve V for pressure feeding the color A and the valve means are finished. 7A closes on a daily basis, and at the same time as this valve closing, or after a time difference of a few thousand seconds, solenoid valve SM is engaged, and pressurized air flows into the air cylinder device of the valve means 7M, causing the air cylinder device to operate. The valve means 7M opens, and high-pressure cleaning air is supplied from the supply pipe 6M to the valve means 7A for color A of the color changer 70, the collecting hole, the paint supply pipe 10, the valve means 101 of the color changer 100, and the collecting hole. , paint supply pipe 4
0. Clean the powder remaining on the wall inside the auto spray gun 50. In this first cleaning step, it is more preferable to open and close the valve means 7M in a pulse manner to intermittent cleaning in a pulse manner. Next, at the same time as the predetermined cleaning time t has passed and the valve means 7M closes, or after a slight time difference, the valve means 1
01 closes. At this point, the cleaning air valve means 104 of the color changer 100 starts opening and closing intermittently, and the second pulse cleaning of the paint passage from the color changer 100 to the auto spray gun 5 is started.
After the predetermined cleaning time elapses, the valve means 1
04 is closed and cleaning is completed. By this second cleaning, the powder paint that has accumulated or has been pressed onto the corners of the walls of the paint passage or areas where the air flow is weak is almost completely cleaned. After the valve means 104 is closed, the air valve for pressure feeding E color, the paint valve of the Venturi mechanism attached to the hopper for E color, and the valve means 78 and 102 of the primary and secondary color changers are sequentially operated. Since the valve is opened and E color powder paint is discharged from the auto spray gun 50, E color painting is started. You can also change colors within the same group, for example from color A (e.g. white) to color B (
For example, when changing the color to ivory, the first cleaning is performed to prevent an excessively dull color, but the second cleaning described above is not necessarily necessary, and after the first cleaning. The air valve for pumping B color, the paint valve of the venturi mechanism 5, and the valve means 7B, 101 can be immediately opened to start painting a new color.Since the color change is between similar colors, it is also possible to change the color between different colors. In comparison, the cleaning time can be significantly reduced for both powder coatings and solvent-based coatings. As explained in detail above, a paint with a paint color that can tolerate warm colors can be selected using one color changer, and such color changers 70, 80, and 90 are installed in the first stage for each color paint supply system. The color changers 70, 80, and 9 are arranged in parallel, and the paint selected by these color changers is selected by the second color changer 100, which is arranged in series with the first color changers 70, 80, and 9. As a result, the number of valve means of the second stage color changer 100 can be reduced (in the case of the embodiment, 101, 102, 10
3,104), the color changer can be made compact, so the second stage self-powered color changer 100 is arranged above the spray gun 50, and the paint supply pipe 40 connecting the two is arranged vertically. can be integrally connected to the drive element 105 of the reciprocator.

Therefore, the paint supply pipe 40 through which paints that are likely to cause color mixing, for example, powder paints such as white and red, is arranged to be easy to wash or clean, and the length of the paint supply pipe 40 can be made extremely short. Therefore, only this part is
In the next wash, the pot can be thoroughly cleaned. Furthermore, the first color changer 70'80,
The second stage color changer is installed on the side of the reciprocator, and is connected to the drive element of the reciprocater as described above, so the paint supply pipe is 10, 20, and 30 had to be made long, and even after the air blow cleaning, there was a relatively large amount of powder paint on the inner wall of this supply pipe due to the small outer diameter of the powder paint and the wall surface. Powder paint tends to remain because the air flow velocity in very close areas is extremely slow, and it also tends to remain on uneven parts of the wall surface that come into contact with the paint of the first stage color changer, but the method and apparatus according to the present invention Valve means 101 of the first stage color changer 70, paint supply pipe 10, and second stage color changer 100; color changer 80, paint supply pipe 20, valve means 102 of the color changer 100: color changer 90, the paint supply pipe 30, and the valve means 103 of the color changer 100, the residual paint and the paint after color change are paints that can tolerate each other with a slightly warmer color, so this problem has not been solved particularly in the past. Warm colors do not occur when changing colors with powder paints, which were previously used, and even with solvent-based paints, due to the reasons mentioned above, the cleaning time and amount of solvent used for cleaning are reduced when changing colors. This method has outstanding effects, such as achieving savings of .

[Brief explanation of drawings]

FIG. 1 is a system diagram showing the main parts of a coating apparatus according to the present invention, and FIG. 2 is an explanatory diagram of a color changer program. IA, IB, IC, ID...Paint supply device, 2
A, 28, 2C, 2D...hoppa, 3A, 3B, 3C,
3D...Paint supply pipe, 4A, 4B, 4C, 4
D...Cyclone, 5A...Air piping, 6
A, 6B,..., 6M... Supply pipe, 7A, 7
B,...7M... Valve means, 8... Control air circuit, 8A, 8B,..., 8M...
Pipe line, 10, 20, 30...Paint supply pipe, 50
... Spray gun, 51 ... High voltage cable, 52 ... Pattern air supply conduit, 7
0,80,90,100...Color changer, 8
1... Branch pipe, 101, 102, 103, 10
4... Valve means, 105... Reciprocator driver, R... Main air supply pipe, RA...
...Regulator, V...Air switching valve, F...
・Phil Yu, RS. ...Air regulator, 1.
...Oh, SA, SB,..., SM...
...Solenoid valve. Figure 2 of the ship

Claims (1)

[Claims] 1. A method for dividing paints from a plurality of paint supply pipes into groups, selecting one paint from each group, selecting one paint from among these selected paints, and applying this selection. A painting method characterized by supplying the collected paint to a spray gun for painting. 2. The method according to claim 1, wherein the paints are grouped by paint color that allows color mixing. 3. The method according to claim 1 or 2, wherein the paint is a powder. 4 A paint supply pipe divided into a plurality of groups, a color changer attached to each group that selects one paint, another color changer that selects between these selected paints, and a color changer that selects one of these selected paints, and 1. A coating device comprising: a spray gun that performs coating by receiving supplied paint. 5. The apparatus according to claim 4, characterized in that a separate color changer is provided integrally with the spray gun. 6. The device according to claim 5, characterized in that a separate color changer is provided above the spray gun.