JP3210475B2 - Body top coating method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the operation of a body topcoating process in a vehicle production line, and more particularly to a body topcoating method which simplifies a body coating process for applying a dark base coat.

[0002]

2. Description of the Related Art In a completed vehicle plant comprising the steps of pressing, welding, painting and assembling, a processing order plan of vehicles for each production line, that is, a plan of which types of vehicles are to be produced and in which order are prepared. Production is being carried out according to the plan. Therefore, in the above coating process,
The paint color is determined based on the vehicle type information (including paint color information) given to the body flowing on the line, the color is changed, and the painting is performed by an automatic painting machine or an air gun on hand. . The coating is performed in the order of undercoating, intermediate coating, and topcoating. In the basecoat coating process of the topcoating, a two-stage coating method is usually employed.

[0003]

In the above-mentioned base coat coating process of the top coat, in order to carry out the production according to the processing order plan, all the bodies are uniformly subjected to 2 steps.
A step coat had been applied. For this reason, there has been a problem that excessive coating is performed on a body of a dark color system in which the coating color is one-step coating.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems of the prior art, and an object of the present invention is to eliminate the use of excessive paint on a dark-colored body and use the same. An object of the present invention is to provide a method for overcoating a body that can reduce paint and energy.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a coating method for applying a top coat base coat to a body of a vehicle by recoating, and the coating method is carried by a continuous conveyor. Among the above-mentioned bodies, a body to be coated with a dark aluminum-based, pearl-based, or solid-based paint is determined, and the base coat coating of the second and subsequent stages of the determined body is omitted.

[0006]

In the method of the present invention, the body to be coated with a dark aluminum-based, pearl-based or solid-based paint does not need to be coated with a base coat in the second and subsequent steps, so that the film thickness of the top coat is appropriate. Become something.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Here, FIG. 1 is a block diagram showing an example of the flow of the overcoating process based on the present invention. As shown in the figure, the body transported from the intermediate coating process, which is the previous process,
Vehicle type information (11-digit ASCI
I code. The paint color information is included. ), It is determined whether the body is to be applied with a dark aluminum-based, pearl-based, or solid-based paint color, or is to be a body to be applied with another paint color.

For the body for applying the deep color, a top coat base coat by electrostatic coating is applied only once, and for the body for applying other non-dark colors, the first stage (electrostatic coating) and the second Perform base coat painting by stage (air gun painting) and send to each clear coat painting process.

FIG. 1 merely shows the flow of the painting process. In an actual line, the line may be branched as shown in FIG. 1; however, the processing order plan is not disturbed. Preferably, all bodies are painted on the same line. That is, based on the dark color and non-dark color coating information, all the bodies are painted while adjusting the conditions of the first stage electrostatic painting, and in the second stage, the painting of the dark colored body is performed. It is preferable to take a measure of omitting.

The determination of the dark color or the non-dark color can be easily made by measuring the L value in Table 1 below using an apparatus such as a Suga tester: SM-5. The L value is obtained by subdividing the lightness (Value: 10 steps) in the known Munsell colorimetric method, and the lightness of each color from black to white is divided into 100 steps from 0 to 100 ( However, in this table, the display is simplified for every five stages.) It should be noted that specific color examples are also shown in the table.

[0011]

[Table 1]

FIG. 2 is a schematic view showing an example of the automatic electrostatic coating apparatus according to the present invention. This electrostatic automatic coating apparatus 1
Φ50m to surround the body 2 placed on the line
electrostatic coating machine 4a-4c equipped with m mini-bells 3a-3i
Is arranged. The electrostatic coating machines 4a to 4c are provided with a reciprocator and a bell swing device. At the time of painting, the mini-bells 3a to 3i are
Is on the cathode side, and the body 2 is on the anode side, and a coating liquid is supplied from a coating tank (not shown) to each of the mini-bells 3a to 3i to perform coating.

Hereinafter, examples of the present invention will be described in more detail together with comparative examples. As an example based on the present invention, the body 2 for applying an aluminum-based, pearl-based, and solid-based paint having an L value of 35 or less in Table 1 above was determined to be a dark-colored body, and the body 2 determined to be dark-colored is shown in Table 2 below. Undercoating was performed under the indicated coating conditions. At this time, the coating amount per unit was 1.82 liters.

[0014]

[Table 2]

Each item in Table 2 is described below. "Top" ... Painter for body horizontal surfaces (bonnet, roof, trunk) (4a in Fig. 2) "L Side" ... Painter on left side of body (4b) "R Side" ... Paint on right side of body Machines (4c, same) "Top 1GUN, 2GUN, 3GUN ... corresponding to minibell 3a, 3b, 3c respectively""L Side 1GUN, 2GUN, 3GUN" ... minibell 3d, 3e, 3
Corresponds to f "R Side 1GUN, 2GUN, 3GUN" ... Minibell 3g, 3h, 3
i Corresponds to each "Cone distance": Distance from the center of the mini bell to the body surface "HV": High voltage for electrostatic coating "Discharge amount": Discharge amount of coating liquid "SA": Shaping air (coating pattern) (The air that controls the width.) “Heating speed”… Mini bell speed “Reciprocating speed”… Reciprocator moving speed “Relative speed”… Speed of mini bell and body

Next, as a comparative example, under the coating conditions shown in Table 3 below, the top coat of the first stage and the second stage was applied to the body 2 determined to be the same dark color as in the example. At this time, the amount of coating per unit is mini bell coating 1.
2 liters, 2.2 liters of air gun painting, total 3.
It was 4 liters.

[0017]

[Table 3]

Each item in Table 3 is described below (items not described are the same as in Table 2). "Top 1GUN, 2GUN, 3GUN" ... mini bell or air gun (corresponds to 3a, 3b, 3c in Fig.2) "L Side 1GUN, 2GUN, 3GUN" ... mini bell or air gun (corresponds to 3d, 3e, 3f respectively) ) "R Side 1GUN, 2GUN, 3GUN" ... Mini bell or air gun (corresponding to 3g, 3h, 3i respectively) "Atomization air" ... Atomization pressure of air gun "Can distance" ... Mini bell or air gun center to body surface Distance "Relative speed": Speed at which the minibell or air gun and the body are opposed

As is clear from the above Examples and Comparative Examples, it was possible to reduce 1.58 liters by subtracting the coating amount per unit. Further, as is clear from the numerical values of the embodiment of Table 2 and the first stage of Table 3,
Variation of coating color tone by shortening "gun distance" in "TOP", increasing "reciprocating speed" and decreasing "relative speed", increasing "HV" and "ejection rate", and adjusting "SA" Were achieved without the occurrence of defects such as

[0020]

As described above, according to the method of the present invention, of the bodies conveyed by the continuous conveyor, a body to be coated with a dark aluminum-based, pearl-based or solid-based paint is determined. 2 of this determined body
Since the base coat coating after the first step is omitted, the number of coating steps can be reduced, and further, the amount of coating and energy can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of the flow of a topcoating process based on the present invention.

FIG. 2 is a schematic view showing an example of an automatic electrostatic coating apparatus according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Automatic electrostatic coating device, 2 ... Body, 3a-3i ... Mini bell, 4a-4c ... Electrostatic coating machine, 5 ... High voltage generator.

Claims (1)

(57) [Claims] 1. A coating method for applying a top coat base coat to a body of a vehicle by over-coating, wherein the coating method is performed by using a dark aluminum-based, pearl-based, and solid-based body among the bodies conveyed by a continuous conveyor. A method for overcoating a body, comprising determining a body to be coated with a paint, and omitting a second basecoat coating of the determined body.