JP2001017913A - 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 executing the treatment of the powder coating stage in the state of closing the aperture 2 with the cap 3, then opening the aperture 2, removing the powder coating materials sticking to the peripheral edge 2a of the aperture 2 and the peripheral edge 3a of the cap 3 and. thereafter, executing the treatment of the stages after the hot melt treating stage. As a result, the stage is shifted to the electrodeposition coating stage through the hot melt treating stage after the powder coating materials adhered here and there to the peripheral edges of the apertures and the peripheral edges of the caps are removed and, therefore, the electrodeposition coating films may be surely formed over the entire surface of the peripheral edges of the apertures and the peripheral edges of the caps.

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 after the completion of the coating process, the coating color of the peripheral portion of the opening and the peripheral portion of the lid may be mottled.

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 pre-treatment step; and a heat melting treatment of heating the powder coating to form a half-baked coating after the completion of the powder coating step. An electrodeposition coating step of forming an electrodeposition coating film on an automobile body at a portion outside the formation area of the half-baked coating film after completion of the hot-melt processing step; and a half-baked coating film after completion of the electrodeposition coating step. And a thermosetting treatment step of thermally curing the electrodeposition coating film, wherein after performing the processing of the powder coating step with the opening closed with a lid, the opening is Open and around the opening Parts and powder coatings removed are adhered to the peripheral portion of the lid, then, and executes the processing of the hot-melt processing step subsequent steps.

According to such a method, the powder coating process in a state where the opening is closed by the lid causes a small gap generated between the peripheral edge of the opening and the peripheral edge of the lid to enter. After removing the sparse powder coating from the peripheral edge of the opening and the peripheral edge of the lid, the process proceeds to the electrodeposition coating process through the heat melting process, so in the electrodeposition coating process,
The electrodeposition coating film can be reliably formed on the entire periphery of the opening and the entire periphery of the lid.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on one embodiment of the present invention shown in the attached 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. It is a figure which shows the coating condition from a coating process to 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, the vehicle body 1 is subjected to a pre-treatment and a pre-coating process such as draining and drying, which is performed on the vehicle body 1. A powder coating step of applying a powder coating to the outer surface of the device 1; a portion for opening the opening 2 and removing the powder coating attached to the peripheral portion 2a of the opening 2 and the peripheral portion 3a of the lid 3; Powder paint removal process, car body 1
Heat treatment in a powder melting furnace (not shown), an electrodeposition coating step of applying an electrodeposition coating to the automobile body 1 by immersion in an electrodeposition liquid, and thermally curing the powder coating and the electrodeposition coating The thermosetting process is sequentially performed in this order. After the thermosetting process, intermediate coating, top coating, and the like are performed.

In FIG. 3, in the powder coating process after the pre-coating process, as shown in FIG. 3 (a), the opening 2 is closed with the lid 3 and the entire outer surface of the vehicle body 1 is covered. The powder coating is performed so as to form the powder coating film 4. At this time, a small amount of powder coating material enters a small gap 5 formed between the peripheral edge 2a of the opening 2 and the peripheral edge 3a of the lid 3, and the peripheral edge 2a of the opening 2 and the lid 3 Rim 3 of
A sparsely adheres to a.

In the partial powder paint removing step following the powder coating step, the lid 3 is opened to open the opening 2 as shown in FIG. The peripheral portion 2a of the opening 2 and the peripheral portion 3a of the lid 3 are formed by a jet or suction by suction means (not shown).
The powder paint sparsely adhered is removed.

In the heat melting process following the partial powder paint removal process, the automobile body 1 with the opening 2 closed by the lid 3 is fed into a melting furnace to perform the heat melting process. FIG. 3 shows the surface of the automobile body 1 according to the melting process.
As shown in (c), a half-baked coating film 7 is formed.

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, the electrodeposition coating is performed on the inner surface side of the automobile body 1 or the like that is out of the target area of the powder coating. However, in the partial powder paint removing step, the peripheral edge 2a of the opening 2 and the peripheral edge 3a of the lid 3 are in a state where the metal surface faces the outer surface. As shown in FIG. 3D, the electrodeposition coating film 8 is also formed on the entire periphery 3a.

As described above, the powder coating process with the opening 2 closed by the lid 3 reduces the gap 5 between the peripheral edge 2a of the opening 2 and the peripheral edge 3a of the lid 3. The powder paint sparsely attached due to the ingress of the paint is removed in the partial powder paint removal step by the peripheral portion 2 a of the opening 2 and the lid 3.
After being removed from the peripheral portion 3a of the metal plate, the process proceeds to the electrodeposition coating process through the heat melting process, so that in the electrodeposition coating process, the peripheral portion 2a of the opening 2 and the peripheral portion 3a of the lid 3 expose the metal surface. It is still allowed. Therefore, the peripheral portion 2 of the opening 2
The electrodeposition coating film 8 can be reliably formed on the entire surface of the peripheral portion 3 a of the cover 3 and the lid 3.

Although the embodiments of the present invention have been described in detail above, 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 appended claims. It is possible to do.

[0017]

As described above, according to the present invention, after the powder coating sparsely adhered to the peripheral portion of the opening and the peripheral portion of the lid is removed, the electrodeposition coating is performed through a heat melting process. Since the process proceeds to the step, in the electrodeposition coating step, the electrodeposition coating film can be reliably formed on the entire periphery of the opening and the periphery of the lid.

[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 powder coating step to an electrodeposition coating step.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Automobile body 2 ... Opening 2a ... Perimeter of opening 3 ... Lid 3a ... Peripheral of lid 4 ... Powder coating 7 ... Half bake coating Membrane 8 ・ ・ ・ Electrodeposition coating

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B05D 7/24 301 B05D 7/24 301A C25D 13/00 C25D 13/00 E 13/20 13/20 C / / B05B 5/025 B05B 5/025 F term (reference) 4D075 BB26Z BB29Z BB89Z DA35 DB02 DC12 EA02 4F034 AA01 BA00 4F042 AA09 AB03 CC03 CC09 DB00

Claims (1)

[Claims] An automobile body (1) having an opening (2) and a lid (3) for opening and closing the opening (2).
A coating pre-treatment step of applying a coating pre-treatment to the car body; a powder coating step of forming a powder coating film (4) on the outer surface of the automobile body (1) after the completion of the coating pre-treatment step; After the completion of the above, the powder coating (4) is heated to form a half-baked coating (7) by heating, and after the completion of the hot-melting processing, a portion deviating from the formation area of the half-baked coating (7) 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 for coating an automobile body including a curing treatment step, after performing the processing of the powder coating step with the opening (2) closed with a lid (3), the opening (2) is opened. And the peripheral portion (2a) of the opening (2) and the peripheral portion (3a) of the lid (3). Adhere to the powder coating was removed and, thereafter, a method of painting an automobile body, wherein performing the process of hot-melt processing step subsequent steps.