JP2001017912A - Method for coating automotive body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely form electrodeposition coating films over the entire surface at the peripheral edges of apertures and the peripheral edges of caps, in a method for coating automotive bodies including a powder coating stage after a coating pretreatment, a hot melt treating stage, an electrodeposition coating stage and a thermal curing treating stage. SOLUTION: This coating method consists in masking the peripheral edge 2a of the aperture 2 and the peripheral edge 3a of the cap 3 with masking materials 4 before the powder coating stage for forming the powder coating films 5 on the outside surface of the automotive body in the state of closing the aperture 2 with the cap 3. The masking materials 4 are removed by either between the powder coating stage and the hot melt treating stage and between the hot melt treating stage and the electrodeposition coating stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coating an automobile body, and in particular, includes a powder coating step, a hot-melt processing step, an electrodeposition coating step, and a thermosetting step on an automobile body after pre-coating. The present invention relates to an improvement in a coating method for an automobile body.

[0002]

2. Description of the Related Art Conventionally, such a coating method for an automobile body has been described as follows.
For example, JP-B-56-10397 and JP-B-6-10397
It is already known in Japanese Patent Application Laid-Open No. 2-2640 and the like.

[0003]

An automobile body is provided with an opening for an occupant to get on and off the vehicle and a cover such as a door for opening and closing the opening. Although the gap between the periphery of the opening and the periphery of the lid is sealed with rubber or the like, when the opening is closed with the lid in the coating process of the automobile body, the periphery of the opening and the lid are closed. There remains a slight gap between the peripheral edges of. Thus, in the conventional powder coating process, the powder coating process is performed while the opening is closed with the lid, and the powder coating is difficult to enter the small gap, so that a small amount of powder is coated. Only the paint enters the gap and adheres sparsely to the periphery of the opening and the periphery of the lid. On the other hand, in the electrodeposition coating process after the heat melting process in which the powder coating is made into a half-baked coating film, the electrodeposition liquid sufficiently enters even a small gap. Since the paint is sparsely adhered, the electrodeposition liquid adheres only to portions except for the sparsely adhered powder coating on the periphery of the opening and the periphery of the lid to form an electrodeposition coating. As a result, there is a possibility that the coating color of the peripheral portion of the opening and the peripheral portion of the lid may become mottled after the completion of the coating process.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a method of coating an automobile body capable of reliably forming an electrodeposition coating film on the entire periphery of an opening and the periphery of a lid. The purpose is to provide.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a painting pre-treatment step for applying a painting pre-treatment to an automobile body having an opening and a lid for opening and closing the opening. A powder coating step of forming a powder coating on the outer surface of the vehicle body after completion of the coating pretreatment step, and heating and melting the powder coating to form a half-baked coating after completion of the powder coating step A treatment step, an electrodeposition coating step of forming an electrodeposition coating film on an automobile body in a portion outside the formation region of the half-bake coating film after the completion of the heat melting treatment step, and a half-bake coating after the completion of the electrodeposition coating step. A heat curing step of thermally curing the film and the electrodeposited film, wherein a powder coating film is formed on the outer surface of the vehicle body with the opening closed by a lid. Before the body painting process, The edge and the peripheral edge of the lid are masked with a masking material, and the masking material is provided between the powder coating step and the hot melt processing step, and between the hot melt processing step and the electrodeposition coating step. Is removed.

According to such a method, the periphery of the opening and the periphery of the lid are masked with a masking material before the powder coating step, so that the opening is closed by the lid. When a small amount of powder paint enters the gap between the two peripheral portions in the powder coating process, the powder paint adheres to the masking material. In addition, since the masking material is removed after the powder coating step and before the electrodeposition coating step, in the electrodeposition coating step, the periphery of the opening and the periphery of the lid cover the metal surface. Since it is exposed, the electrodeposition coating film can be reliably formed on the entire periphery of the opening and the periphery of the lid.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

1 to 3 show an embodiment of the present invention. FIG. 1 is a perspective view showing a side portion of an automobile, FIG. 2 is a view showing a painting process of an automobile body, and FIG. 3 is a masking process. It is a figure which shows the coating situation from an electrodeposition coating process sequentially.

First, in FIG. 1, an opening 2 such as an opening for an occupant to get on and off is provided in a vehicle body main portion 1a constituting a main portion of the vehicle body 1, and the vehicle body 1 is formed together with the vehicle body main portion 1a. The opening 2 is opened and closed with a lid 3 such as a door.

In FIG. 2, when painting the vehicle body 1, a pre-coating step of applying pre-treatment and pre-coating treatment such as draining and drying to the vehicle body 1, the opening 2 and the lid with the opening 2 opened. 3, a masking process of applying a masking process to the peripheral portions 2a, 3a, a powder coating process of applying a powder coating to the outer surface of the vehicle body 1 with the opening 2 closed by the lid 3, and a masking process in the masking process. A masking removing step of canceling the processing, a heat melting processing step of heating the vehicle body 1 in a powder melting furnace (not shown), an electrodeposition coating step of applying an electrodeposition coating to the vehicle body 1 by dipping in an electrodeposition liquid, and The thermosetting process for thermally curing the powder coating and the electrodeposition coating is sequentially performed in this order, and after the thermosetting process, intermediate coating and top coating are performed.

Referring to FIG. 3, in a masking step after the pre-coating treatment step, as shown in FIG. The portion 2 a and the peripheral portion 3 a of the lid 3 are masked with a masking material 4.

In the powder coating step after the masking step, as shown in FIG. 3B, the powder coating 5 is applied to the entire outer surface of the vehicle body 1 with the opening 2 closed with the lid 3. The powder coating is performed to form. At this time, even if a small amount of powder paint enters the small gap 6 generated between the peripheral edge 2a of the opening 2 and the peripheral edge 3a of the lid 3, the peripheral edges 2a, 3a are masked. Is masked with the masking material 4, the powder coating material that has entered the gap 6 adheres to the masking material 4.

In the masking removing step following the powder coating step, as shown in FIG. 3 (c), the opening 2 is opened and the peripheral edge 2a of the opening 2 and the peripheral edge 3a of the lid 3 are covered. Peel off the masking material 4. Thereby, the peripheral portion 2a of the opening 2 and the peripheral portion 3a of the lid 3 are in a state where the metal surface is exposed.

In the heat melting process following the masking removal process, the automobile body 1 with the opening 2 closed by the lid 3 is fed into the melting furnace to execute the heat melting process. Thus, a half-baked coating film 7 is formed on the surface of the automobile body 1 as shown in FIG.

In the electrodeposition coating process following the heat melting process,
A portion where the metal surface of the car body 1 is exposed,
That is, an electrodeposition coating is applied to the inner surface side or the like of the vehicle body 1 that is out of the target area of the powder coating, and the vehicle body 1 includes the peripheral portion 2 a of the opening 2, the peripheral portion 3 a of the lid 3, and the inner surface of the lid 3. As shown in FIG. 3 (e), an electrodeposition coating film 8 is formed on the inner surface side.

As described above, by performing the masking with the masking material 4 on the peripheral portion 2a of the opening 2 and the peripheral portion 3a of the lid 3 immediately before the powder coating process, both the peripheral portions 2a, When a small amount of powder coating material enters the gap 6 between 3a, the powder coating material adheres to the masking material 4. Moreover, since the masking material 4 is removed between the powder coating step and the hot-melt processing step, in the electrodeposition coating step, the entire periphery 2a of the opening 2 and the entire periphery 3a of the lid 3 are made of metal. Since the surface is exposed, the electrodeposition coating film 8 can be reliably formed on the entire periphery 2 a of the opening 2 and the periphery 3 a of the lid 3.

FIG. 4 shows another embodiment of the present invention, and portions corresponding to the above embodiment are denoted by the same reference numerals.

In coating the automobile body 1, a masking step is inserted between the pre-coating step and the powder coating step, and a masking removing step is inserted between the hot-melt processing step and the electrodeposition coating step.

That is, in the masking step, FIG.
As shown by, the peripheral portion 2a of the opening 2 and the peripheral portion 3a of the lid 3 are masked with a masking material 4, and FIG.
After the powder coating process shown in FIG. 4 and the heat melting process shown in FIG. 4C are sequentially performed, a masking removing process is performed as shown in FIG. The masking material 4 covering the peripheral edge 3a of the body 3 is peeled off. Thus, in the electrodeposition coating step shown in FIG. 4E, the peripheral portion 2a of the opening 2 and the peripheral portion 3a of the lid 3 are formed.
However, the metal surface is exposed, and the electrodeposition coating film 8 is formed on the entire surface of the peripheral portions 2a and 3a.

According to this embodiment, the peripheral portion 2a of the opening 2 and the peripheral portion 3a of the lid 3 are also formed in the electrodeposition coating process.
Is in a state where the metal surface is exposed.
The electrodeposited coating film 8 can be reliably formed on the entire periphery 2a of the cover 3 and the periphery 3a of the lid 3. As described above, the embodiments of the present invention have been described in detail. However, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. It is possible.

[0021]

As described above, according to the present invention, the peripheral portion of the opening and the peripheral portion of the lid are masked with a masking material before the powder coating step, and after the powder coating step, the electric power is applied. By removing the masking material before the coating process, in the electrodeposition coating process, the peripheral portion of the opening and the peripheral portion of the lid expose the metal surface, and the peripheral portion of the opening and the entire peripheral portion of the lid are exposed. The electrodeposition coating film can be formed reliably.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a side portion of an automobile.

FIG. 2 is a view showing a painting process of an automobile body.

FIG. 3 is a view sequentially showing a coating state from a masking step to an electrodeposition coating step.

FIG. 4 is a view sequentially showing a coating state from a masking step to an electrodeposition coating step of another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Automobile body 2 ... Opening 2a ... Perimeter of opening 3 ... Lid 3a ... Peripheral of lid 4 ... Masking material 5 ... Powder coating 7: half-baked coating 8: electrodeposition coating

Claims (1)

[Claims] An automobile body (1) having an opening (2) and a lid (3) for opening and closing the opening (2).
Pre-coating process for applying a pre-coating process to a vehicle, a powder coating process for forming a powder coating film (5) on the outer surface of the vehicle body (1) after completion of the pre-coating process, and the powder coating process After the completion of the step, the powder coating film (5) is heated to form a half-baked coating film (7), and a portion deviating from the formation region of the half-baked coating film (7) after the completion of the hot-melting processing step. An electrodeposition coating step of forming an electrodeposition coating film (8) on the automobile body (1) by using the heat treatment for thermally curing the half-baked coating film (7) and the electrodeposition coating film (8) after the completion of the electrodeposition coating step. In a method of coating an automobile body including a curing step, a powder coating film (5) is formed on an outer surface of the automobile body (1) with the opening (2) closed with a lid (3). Prior to the powder coating step, the periphery (2a) of the opening (2) and the periphery of the lid (3) 3a) a masking member (4)
Wherein the masking material (4) is removed between the powder coating step and the hot melt processing step and between the hot melt processing step and the electrodeposition coating step. How to paint the body.