JP2001032096A - Electrodeposition coating method for automotive body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To subject automotive bodies varying in corrosion conditions and the number of finish coats to an electrodeposition coating in compliance with the respective corrosion conditions and the number of the finish coats. SOLUTION: Plural electrodeposition tanks (11) to (14) varying in electrodeposition coating materials and set voltage are installed. The automotive bodies varying in the corrosion conditions and the number of the finish coats are selectively immersed in the electrodeposition coating materials of the electrodeposition tankselectrodeposition coating in compliance with the respectivecorrosion conditions and the number of the finish coats.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodeposition coating method used as an undercoat for an automobile body.

[0002]

2. Description of the Related Art At present, electrodeposition coating is generally used as undercoating of an automobile body. As shown in FIG. 6, the electrodeposition coating of the vehicle body is performed by moving the vehicle body (1) on the hanger rail (2) while moving the vehicle body (1) on the hanger rail (2). Then, the body (1) is immersed in the electrodeposition paint (4) of the electrodeposition tank (3), and the body (1) is used as a cathode and between the anode and the anode separately provided in the electrodeposition paint (4). This is a coating method in which a set voltage is applied and a coating film is formed on the vehicle body (1) by an electrochemical reaction.

[0003]

In the conventional electrodeposition coating of an automobile body, a single electrodeposition tank (4) is used.
Usually, the same electrodeposition paint is used under constant conditions regardless of the corrosion conditions and the number of overcoats. for that reason,
When electrodeposition coating multiple types of vehicles with different corrosion conditions and number of top coats, the electrodeposition paint and voltage etc. are set according to the vehicle for the area where the corrosive environment is the most severe,
A problem arises in that a car body suitable for an area having mild corrosion conditions has an excessively large coating film thickness.

On the other hand, in the case of a vehicle body for a two-coat vehicle composed of an electrodeposition coating and a topcoat, a topcoat is applied by using an electrodeposition paint for a three-coat vehicle (a vehicle composed of an electrodeposition coating, an intermediate coating and a topcoat). Since the electrodeposition coating film is destroyed by the ultraviolet light transmitted through the coating material, it is necessary to use a special electrodeposition coating material for two-coat vehicles.

[0005]

According to the present invention, in order to solve the above-mentioned problems, an electrodeposition paint and a plurality of electrodeposition tanks having different set voltages are installed, and a vehicle body is selectively placed in the electrodeposition paint of the electrodeposition tank. It is characterized by being immersed in an electrodeposition coating.

[0006]

FIG. 1 is a block diagram showing an embodiment of the present invention.
A description will be given based on FIGS. In this embodiment, the body (A) for a three-coat vehicle suitable for a region having a moderate corrosive environment, the body (B) for a three-coat vehicle suitable for a region with a severe corrosive environment, and the vehicle body (B) for a two-coat vehicle C) is to be electrodeposited.

FIG. 1 shows first to fourth electrodeposition tanks (11) to (14) used in the method of electrodeposition coating an automobile body according to the present invention.
FIG. 2 is a schematic plan view showing the installation relationship of a first electrodeposition tank (1).
1), the second electrodeposition tank (12) and the third electrodeposition tank (1).
3) are arranged in parallel, and the fourth electrodeposition tank (1)
4) is arranged in series after the second electrodeposition tank (12).

As shown in FIG. 2, the first electrodeposition tank (11) is completely immersed in the body (A) with an electrodeposition paint (15) for a three-coat vehicle suitable for a region having a mild corrosive environment. The voltage is set in accordance with the electrodeposition coating (15) and the electrodeposition coating for a three-coat vehicle suitable for an area where the corrosive environment is moderate.

As shown in FIG. 3, the second electrodeposition tank (12) is capable of completely immersing the vehicle body (B) in an electrodeposition paint (16) for a three-coat vehicle suitable for a region having a severe corrosive environment. The voltage is set in accordance with the electrodeposition coating (16) and the electrodeposition coating for a three-coat vehicle for an area where the corrosive environment is severe.

As shown in FIG. 4, the third electrodeposition tank (13) contains a special electrodeposition paint (17) for a two-coat vehicle so that the vehicle body (C) can be completely immersed therein. The voltage is set according to the electrodeposition paint (17) and the electrodeposition paint for a two-coat vehicle.

As shown in FIG. 5, the fourth electrodeposition tank (14) is provided with an electrodeposition paint (18) for improving corrosion resistance for a three-coat vehicle suitable for an area having a severe corrosive environment. The half (lower part) is accommodated so that it can be immersed, and the voltage is set in accordance with the rust-preventing power-improving electrodeposition paint (18).

A first electrodeposition tank (11) and a second electrodeposition tank (1)
A selection conveyor (19) is provided in front of the second and third electrodeposition tanks (13).
9), the vehicle body (A) transported by the transport means (not shown) is the first electrodeposition tank (11), the vehicle body (B) is the second electrodeposition tank (12), and the vehicle body (C) is the third electrodeposition tank. Electroplating tank (13)
To be transported selectively.

Next, the electrodeposition coating method for an automobile body according to the present invention will be described.

First, when a car body (A) for a three-coat vehicle directed to an area having a moderately corrosive environment is transported, the car body (A) is selected on a first conveyor (19) by a selection conveyor (19).
Then, the vehicle body (A) is immersed in the electrodeposition paint (15) of the first electrodeposition tank (11) by a conveying means with a lifting device (not shown). Then, a set voltage is applied between the vehicle body (A) and the electrodes provided in the electrodeposition paint (15), and the vehicle (A) is subjected to electrodeposition coating for a three-coat vehicle suitable for a region having a moderately corrosive environment. Do. Thereafter, the vehicle body (A) on which the electrodeposition coating has been applied is taken out of the first electrodeposition tank (11) by the transporting means with the elevating device, and is transferred to the next intermediate coating step by the transporting means (not shown). Transport.

Next, when a vehicle body (B) for a three-coat vehicle directed to an area having a severe corrosive environment is transported, the vehicle body (B)
Is transported to the second electrodeposition tank (12) by the selection conveyor (19), and the vehicle body (B) is transported by transport means with an elevating device (not shown).
Is immersed in the electrodeposition paint (16) of the second electrodeposition tank (12). Then, a set voltage is applied between the vehicle body (B) and the electrode provided in the electrodeposition paint (16) to perform the preceding electrodeposition coating on the vehicle body (B). Next, the vehicle body (B) on which the preceding electrodeposition coating has been applied is taken out of the second electrodeposition tank (12) by the transporting means with the elevating device, and the rustproofing power of the fourth electrodeposition tank (14) is obtained. About half of the vehicle body (B) is immersed in the improved electrodeposition paint (18). Then, the body (B) and the electrodeposition paint (1
6) A set voltage is applied between the electrode provided therein and electrodeposition coating for improving the rust-preventive force of the latter stage on the vehicle body (B). Thereafter, the vehicle body (B) on which the latter-stage rust-preventive force-improving electrodeposition coating has been applied is taken out of the fourth electrodeposition tank (14) by the transporting means with the elevating device, and the next step is performed by transporting means (not shown). To the intermediate coating process.

Next, when the car body (C) for the two-coat vehicle is conveyed, the car body (C) is conveyed to the third electrodeposition tank (13) by the selection conveyor (19), and is moved up and down (not shown). The vehicle body (C) is immersed in the electrodeposition paint (17) of the third electrodeposition tank (13) by the transport means with the device. Then, a set voltage is applied between the vehicle body (C) and the electrodes provided in the electrodeposition paint (17) to perform the electrodeposition coating for the two-coat vehicle on the vehicle body (A). Thereafter, the body (C) on which the electrodeposition coating has been performed is taken out of the third electrodeposition tank (13) by the transporting means with the elevating device, and
It is conveyed to the next topcoating process by the conveyance means not shown.

In this embodiment, the first to fourth electrodeposition tanks (11) to (1) having different electrodeposition paints and set voltages are used.
Since the body (A), (B) and (C) having different corrosion conditions and the number of top coats are selectively immersed in the electrodeposition paints (14) to (18) of 4), the electrodeposition coating is performed. Vehicle bodies (A), (B), and (C) having different numbers of overcoats can be electrodeposited according to the respective corrosion conditions and the number of overcoats.

The above is an explanation of one embodiment according to the present invention. It goes without saying that the present invention is not limited to this embodiment, and that the design can be changed within the gist of the present invention. For example, the case where four types of electrodeposition tanks are installed and three types of vehicle bodies are subjected to electrodeposition coating has been described. However, the number of electrodeposition tanks is not limited to four, and the number of vehicle bodies is not limited to three types. .

[0019]

As described above, according to the present invention,
A plurality of electrodeposition tanks with different electrodeposition paints and set voltages were installed, and the car body was selectively immersed in the electrodeposition paint in the electrodeposition tank for electrodeposition coating. Can be electrodeposited in accordance with the respective corrosion conditions and the number of overcoats, thereby preventing overpainting of the vehicle body.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing an installation relationship of first to fourth electrodeposition tanks used in an embodiment of an electrodeposition coating method for an automobile body according to the present invention.

FIG. 2 is a schematic diagram of a first electrodeposition tank used in the embodiment of the present invention.

FIG. 3 is a schematic diagram of a second electrodeposition tank used in the embodiment of the present invention.

FIG. 4 is a schematic diagram of a third electrodeposition tank used in the embodiment of the present invention.

FIG. 5 is a schematic view of a fourth electrodeposition tank used in the embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a conventional electrodeposition coating apparatus for an automobile body.

[Explanation of symbols]

A vehicle body for a three-coat vehicle suitable for areas with moderate corrosion conditions B body for a three-coat vehicle suitable for areas with severe corrosion conditions C vehicle body for a two-coat vehicle 11 first electrodeposition tank 12 second electrodeposition tank Reference Signs List 13 Third electrodeposition tank 14 Fourth electrodeposition tank 15 Electrodeposition paint for 3 coat car for areas where corrosion conditions are moderate 16 Electrodeposition paint for 3 coat car for areas where corrosion conditions are severe 17 2 coats Electrodeposition paints for cars 18 Electrodeposition paints to improve rust prevention 19 Selection conveyor

Claims (2)

[Claims] 1. An electrodeposition paint and a plurality of electrodeposition tanks having different set voltages are installed, and an automobile body is selectively immersed in the electrodeposition paint of the electrodeposition tank to perform electrodeposition coating. The method of electrodeposition coating of automobile bodies. 2. The method according to claim 1, wherein the vehicle body is immersed in the electrodeposition paint of two or more of the electrodeposition tanks to perform electrodeposition coating.