JPS60146636A - Rust prevention method for car body parts - Google Patents

Abstract

PURPOSE:To improve rust-prevention performance of such as doors and hoods which are obtained by bending an end part of a panel through hemming processing by bending the first panel end part to the second panel surface side after electrodepositing on a first panel member, and integrating both panels. CONSTITUTION:A door outer panel P1 and an inner panel P2 are respectively electrodeposited to form an electrodeposited coating film Q. One of them is put upon the other, and end part E of the panel P1 is bent to the surface side of the panel P2, allowing both panels P1 and P2 to be integrally formed. Further, before bending the end part E of the pallet P1, an adhesive is applied on a portion where both panels P1 and P2 make contact with each other. The applied film such as electrodeposition, etc., of a door thus formed is maintained not only upon drawing processing but also a mating face between the first and second panel materials, and secure rust-prevention thereof can be accomplished without use of a surface processed steel plate as a panel raw material.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is applicable to automobile body parts, such as doors, hoods, trunk lids, etc., which are formed by bending the ends of panel materials by hemming. Concerning rust prevention methods.

(Prior Art) FIGS. 1A and 1B are diagrams showing an example of an automobile body part without showing a door, and the door D is usually formed by combining an outer panel P1 and an inner panel P2. In order to manufacture such a door D, after forming the outer panel P1 and the inner panel P2 into predetermined shapes by pressing, the end portion E4 of the outer panel P1 is formed.
The outer panel P1 and the inner panel P2 are integrated by bending and sandwiching the inner panel 1]2 between these parts. Next, after performing pretreatment such as chemical conversion treatment on door D, electrodeposition tJ! The product is made into a product after going through various types of coatings such as coating and electrostatic coating.

Rust prevention for doors is achieved by applying a paint film to the surface of the door panel.

However, the outer panel 1) 1 and the inner panel P
In some cases, it was difficult for the paint to penetrate sufficiently into the narrow bag-shaped portion formed by II and the seam between the inner panel and the outer panel during II coating. Therefore, Figure 1 (
As in B), an attempt has been made to use a surface-treated steel sheet having a treated surface S in which one surface of the panel material is previously subjected to anti-rust treatment.

However, the surface treatment 'fJf! When press-forming a steel plate as a panel material, not only is there a risk that the layered or film-like anti-corrosion treated surface will be scraped off, but the steel plate itself is expensive, and the soil that has poor press-formability may be scraped off. There was a problem in that the powder on the treated surface would adhere to the press mold or other panel materials, causing so-called star grains on the outer surface of the panel, degrading the quality.

(Objective of the Invention) The present invention has been made by focusing on the problems of the prior art mentioned above. The purpose of this invention is to improve the rust prevention performance of automobile body parts that are bent.

(Groove Bottom of the Invention) To achieve the above object, the present invention includes a first panel material and a second panel material, and the first panel material and the second panel material are formed by bending the ends of the first panel material. After applying anti-rust coating such as electrodeposition coating to at least the first panel of the automobile body parts formed by integrating the panel material,
While the first panel material and the second panel material are placed together, the end portion of the first panel material is bent toward the surface side of the second panel material, and the first panel material and the second panel material are folded. This is a rust prevention method for automobile body parts characterized by integrating panel materials.

(Example) Hereinafter, one embodiment of the present invention will be explained based on the drawings.

Figures 2 to 6 are process diagrams showing the case where the rust prevention method of the present invention is applied to a door. After pressing the panel P2 (as shown in FIG. 2), the small parts T are spot welded to form the door outer panel P1 and the door inner panel 1, as shown in FIG. molded.

Next, as shown in FIGS. 4(A) and 4(B), the door outer panel P1 and the door outer panel P2 are electrocoated to form an electrocoated film Q on their surfaces to prevent rust. Plan. In addition, before performing electrodeposition coating, pretreatment such as chemical conversion treatment is performed in advance to achieve J3<. In addition, Figure 4 (B) is the same figure (
FIG. 3 is a partially enlarged sectional view of panel P1 and panel P2 shown in FIG.

Then, the door outer panel 1〕1 and the door inner panel
The lower door outer panel when the panel P2 and the lower door outer panel are aligned as shown in FIG.
1) to integrate both panels P1 and 1)2. FIG. 5(B) is a partially enlarged sectional view of the J panel P1 and panel P2 shown in FIG. 5(A). In addition, before folding the end E of the door outer panel 1) 1, both panels P+
, P2 that are in contact with each other are coated with adhesive. Further, as the rust-preventing coating, other coating means other than electrodeposition coating may be used, and furthermore, the rust-preventing coating may be applied only to the inner panel P1 as the first panel scarlet.

For the door D formed in this way, FIG.
After attaching the hinge 1-1 and the like as shown in FIG. 6, the door D is attached to the vehicle body B as shown in FIG.

(Effects of the Invention) As described above, according to the present invention, the first panel material and the second panel material are formed, and the ends of the first panel material are bent to form the first panel material and the second panel material. Among the automobile body parts formed by integrating the shrine and the shrine, at least 1) of the wiring 1 panel shrine is coated with anti-corrosion coating such as electrodeposition coating, and then the first panel tank Δ and Oη are applied to the second panel tank +) Bend the edge of the first panel material to the front side of the second panel to integrate the first panel material and the second panel material. So, drawing process 11
3, of course, the combination of the first panel material and the second panel material! Visually, the paint film is maintained, and reliable rust prevention can be achieved without using C surface-treated steel sheets as the panel material.

[Brief explanation of the drawing]

FIGS. 1A and 1B are schematic diagrams showing a conventional rust prevention method for automobile body parts, and FIGS. 2 to 6 are process diagrams showing an embodiment of the present invention. Pl...door outer panel, 'P2...door inner panel, E...end, B...vehicle body. Patent applicant: Nissan Motor Co., Ltd. (A)

Claims (1)

[Scope of Claims] Consisting of a first panel material and a W12 panel material, an end portion of the first panel material is bent to form a tIJk with the first panel material.
! ? 112 The back side of the automobile body part formed by integrating the panel material with the first panel material and the second panel material is Bend the end of the first panel material toward the surface side of the second panel material while the two panels are together.
A rust prevention method for automobile body parts featuring Nito.