JPS5950389B2 - Paint switching supply method in painting line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a common painting gun that selectively switches and supplies several types of paint based on a color selection command from a computer, such as on an automobile body painting line.

The present invention relates to a coating line in which articles to be coated are individually coated. For example, in the automotive body painting line mentioned above, a so-called 3-coat method is commonly used, in which rust prevention is first performed by dipping, then an intermediate coat is applied, and finally a top coat is applied. A paint switching supply mechanism called a changer selects and supplies paint of the corresponding color to a common paint gun based on a color selection command signal from a computer, thereby individually color-coding automobile bodies. A painting method is used in which the paint is applied using

By the way, when painting high-end models, it is necessary to apply one additional top coat after applying the three coats mentioned above to improve the texture and weather resistance of the paint.
Another topcoat station is installed on the extension of the 3-coat painting line, and when high-end models are brought in, this topcoat station performs a topcoat using a finishing paint with a high proportion of resin. I was dealing with this. However, in that case, a separate top coating station is required, and a paint supply piping system, color changer, painting gun, etc. must be installed, which not only increases equipment costs but also requires separate installation space. I had a problem that I had to deal with.

The present invention has been made in view of such problems, and includes:
At one painting station, it is possible to selectively supply first and second paints of the same color but different resin component ratios to the painting gun as needed, so that the above-mentioned two-time application is possible. It is an object of the present invention to provide a paint switching supply method in a painting line that allows top coating to be performed at the same station.

That is, in the present invention, as described above, the first paint and the second paint used for two top coats differ only in the resin component ratio, and the second paint has a resin added to the first paint. This was done by focusing on the fact that different colors require different amounts of resin to be added. If necessary, resin components are supplied into the first paint at the optimal ratio for the color, and by uniformly mixing, a second paint with a high resin ratio is generated, and then supplied to the painting gun. The basic feature is that

Hereinafter, the present invention will be described in more detail based on illustrated embodiments.

As shown in the drawing, the top coating station 1 on the car body painting line shows that in the case of normal three-coat coating, the car body is transported from the intermediate coating station to the top coating station 1 by a conveyor 2, and then transferred to the water polishing device. After being polished in Step 3 and dried in an oven 4, it is topcoated with a coating gun 6 in a topcoating rebooth 5, dried in an oven 7, and then transported to the next process.

The paint used for this first top coat (hereinafter referred to as the first paint).

) is supplied from each supply tank (not shown) in which pigment, resin, and curing agent are blended and mixed in a predetermined ratio for each color.
The supply pipes 8a, . . . , 8d supply paint to the color changer 10 via paint regulators 9a, . . . , 9d, respectively. , a color selection command signal a applied from a computer (not shown) that controls the production line.
If the color specified this time is different from the previous color, after cleaning the previous first paint with the thinner supplied from the cleaning thinner supply pipe 11, the first paint of the color specified this time is applied. 1 paint is fed to the painting gun 6 through the supply pipe 12 at a predetermined timing, and necessary color painting is performed. In the present invention, the first paint supply pipe 8a
,..., 8d, a resin supply pipe 13 for supplying only the resin to be added to the paint is installed in parallel, and a two-liquid mixer 14 is interposed in the middle of the supply pipe 12, The resin supply pipe 13 is connected to the two-liquid mixer 1 by a connecting pipe 15.
A feeding gear pump 17 driven by a motor 16 is interposed in this connecting pipe 15, and the gear pump 17 is driven to supply resin to the two-liquid mixer 14 through a check valve 18. A resin supply system is provided which mixes the resin into the first paint in the two-liquid mixer 14 to produce a second paint with a high resin component ratio.

The motor 16 that drives the gear pump 17 is controlled by a control circuit 19 which receives at least two of the color selection command signal a and the model signal b as input signals, and the control circuit 19 receives the model signal b. If the model is a 4-coat model, the color changer 10 determines whether it is necessary to apply a second top coat (4 coats) or not (4 coats). Knowing the color of the first paint to be supplied, the drive (time, speed) of the motor 16 is controlled so as to supply the amount of resin added in accordance with the color.

The amount of this resin added varies depending on the color, but when the ratio of pigment to resin in the first paint is in the range of 1/1.2 to 1/10, the ratio of the second paint is 1/1. The optimum value is set within the range of /3 to 1/20.

By configuring the second paint supply system as described above, the second top coat can be performed using the same station 1.

For this reason, as shown in the drawing, a return conveyor 20 is provided to return the automobile body from the carry-in side to the carry-in side of the top coating rest station 1, and the return conveyor 20 allows the car body to pass through the top coat rest station 1 again. All you have to do is apply a topcoat.

In addition, when performing the second top coat, a space is secured in advance by a computer command so that the returned car body can be inserted, and the car body is transported again to the top coat rebooth 5. When the control circuit 19
Then, the motor 16 is started, the first paint sent from the color changer 10 is changed to the second paint in the two-liquid mixer 14, and the second paint is applied by the paint gun 6. Bye.

These controls can be easily performed by a computer.
In the above examples, the present invention was applied to the second top coating of an automobile body, but the present invention is not limited to this, and it goes without saying that the present invention can be applied to multi-colored paint lines in general. Needless to say, the present invention can also be applied to cases where it is necessary to change the resin ratio during the first top coat.

As is clear from the above description, according to the present invention, when painting different colors on the same painting line, it is possible to switch and supply the second paint having a different resin ratio from the first paint as necessary. Moreover, this switching supply method eliminates the need to install another painting station in parallel or separately, and provides the advantage that painting with the second paint can be performed easily and inexpensively at the same station.

[Brief explanation of drawings]

The drawing is a schematic overall explanatory diagram of a painting station to which the method of the present invention is applied. 1... Top coating station, 2... Conveyor, 6
...Painting gun, 8a,..., 8b...First paint supply pipe, 10...Color changer, 13...
Resin supply pipe, 14... Two-liquid mixer, 16... Motor, 17... Gear pump, 19 Motor control circuit.

Claims (1)

[Claims] 1 A first paint supply line that supplies a plurality of first paints each containing a pigment, a resin, and a curing agent mixed in a predetermined ratio corresponding to each color; A color changer that selectively switches a first paint corresponding to an applied color selection signal, and a coating that is connected to the color changer via a connection line and performs painting with the first paint selected by the color changer. In a painting line equipped with at least a paint gun, resin is supplied into the first paint supplied from the color changer to the paint gun at a ratio corresponding to the color selection signal applied from the computer, and the first paint and resin are supplied in a ratio corresponding to the color selection signal applied from the computer. A method for switching and supplying paint in a painting line, characterized in that a second paint having a resin ratio different from that of the first paint is produced by mixing the two paints, and the second paint is supplied to a painting gun.