JPS6254527A - Hemming working method - Google Patents

Abstract

PURPOSE:To prevent the other side panel from being flawed, by curving and forming the tip of a hemming flange part which is formed in a terminal part of a panel, to roughly a bow shape in advance, making the top part of the curved part abut on the other side panel first, and superposing them. CONSTITUTION:The tip part of a hemming flange part 1a which is formed in a terminal part of an outer panel 1 is curved and formed to roughly a bow shape in advance and a curved part 1b is formed. Subsequently, an inner panel 2 is superposed on the panel 1, and by a pre-hemming die 3 having an inclined forming surface 3a, a pre-hemming working is performed to the hemming flange part 1a. In a process in which the flange part 1a is bent, a top part 1c of the curved part 1b abuts on the panel 2 first. When a hemming die 4 further descends, a base part 1d of the flange part 1a and the curved part 1b are crushed, and the whole flange part 1a containing an edge part E of the tip is contacted with the panel 2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a hemming method for applying so-called edge bending to the end of a panel such as an automobile body panel.

Conventional Technology Panel parts such as automobile door panels and trunk lids are generally constructed by hemming and joining an outer panel and an inner panel, and a typical hemming process is shown in Fig. 3. Shown in (A) to (D).

That is, as shown in FIG. 3(A), the flange portion 1 is
The inner panel 2 is superimposed on the outer panel 1 having the bent portion a, and pre-hemming is performed by bending the flange portion 1a to about 45 degrees using a pre-hemming die 3, as shown in FIG. 3(B).

Furthermore, as shown in Figure (C), the pre-hemmed flange portion 1a is bent by a hemming die 4 and overlapped with the inner panel 2, which is the mating panel, and finally as shown in Figure (D). The hemming process is completed as shown.

Problems to be Solved by the Invention In the conventional hemming method, as is clear from FIG. 3(B), the flange portion 1 is
When bending a, a curved portion R is formed at the base of the flange portion 1a.
1 (flange portion 1a on molding surface 3a of pre-hemming die 3)
(parts that do not adhere tightly) occur. When the curvature R3 occurs, as is clear from FIG. 3(C), the edge E at the tip of the flange 1a comes into contact with the inner panel 2 first when hemming is performed using the hemming die 4, and this edge The contact point Q, which is E, moves to point Q in FIG. 3(D) in conjunction with the lowering movement of the hemming die 4. For this reason, scratches occur on the inner panel 2 during the movement of the contact Q, which is the edge portion E, and these scratches tend to cause rust.

Means for Solving the Problems The present invention aims to provide a hemming method that prevents the occurrence of scratches as described above. The tip of the hemming flange is previously curved into a substantially arched shape, and when the hemming flange is bent and overlapped with the mating panel, the top of the curved part is brought into contact with the mating panel first. It is something.

According to the present invention, the top of the curvature portion with a predetermined curvature comes into contact with the mating panel first, instead of the tip end portion of the hemming flange portion as in the conventional case. Even if a sliding movement is performed between the panels, the opposing panel will not be damaged.

Embodiment FIGS. 1A to 1D are diagrams showing a more specific first embodiment of the present invention.

In this embodiment, the tip of the hemming flange 1a formed at the end of the outer panel 1, which is one panel, is curved in advance into a substantially arched shape as shown in FIG. 1(A). A curved portion 1b having a predetermined curvature is formed.

This curved portion 1b is formed at the same time as the hemming flange portion 1a is bent at the end portion of the outer panel 1 in the previous step.

In the pre-hemming process shown in FIG. 1(B), an inner panel 2, which is a mating panel, is superimposed on an outer panel L, and a pre-hemming die 3 having an inclined forming surface 3a as in the conventional case is A pre-hemming process is performed on the hemming flange portion 1a.

In the hemming step shown in FIG. 1(C), the hemming flange portion 1a, which has been previously pre-hemmed, is hemmed using a hemming die 4 having a horizontal forming surface 4a, as in the prior art. That is, the hemming flange portion 1a that has been pre-hemmed is further bent to overlap the hemming flange portion 1a with the inner panel 2.

In this case, as is clear from FIG. 1(C), the top IC of the curved portion 1b first comes into contact with the inner panel 2 in the process of bending the hemming flange portion 1a.

As the hemming die 4 further descends from the state shown in FIG. 1(C), the base 1 of the hemming flange portion 1a
d and the curved portion 1b are gradually crushed, and when the hemming die 4 reaches the lowering limit position, the entire hemming flange portion 1a including the tip edge portion E comes into close contact with the inner panel 2, as shown in FIG. 1(D). The state will be as follows.

Here, in the process of transitioning from the state of FIG. 1(C) to FIG. 1(D), a sliding movement is performed between the top IC of the curved portion 1b and the inner panel 2. Top IC
Since it is not sharp, the inner panel 2 will not be damaged. In addition, the relatively sharp edge portion E at the tip of the hemming flange portion 1a comes into contact with the inner panel 2 for the first time when the hemming die 4 reaches the lowering limit position, so there is no sliding contact between the hemming flange portion 1a and the inner panel 2. No movement is performed.

FIGS. 2A to 2D are views showing a second embodiment of the present invention, in which adhesive S is applied to the so-called hemming joint.

As shown in FIG. 2(A), the adhesive S is applied in a bead shape along the hemming flange portion 1a after the hemming flange portion 1a is bent and before the pre-hemming process. After S is applied, the brihemming process shown in Figure 2 (B) and the process shown in Figure 2 (
Hemming processing is performed through the hemming process of C).

In this case, as it is clear from FIG. 2(C), as the hemming process progresses, the adhesive S in the space R tends to flow out toward the edge E, but the adhesive S flows out from the inner panel 2. and the contact point Q between the top part 1C of the curved part 1b,
This prevents the adhesive S from flowing out to the outside. This is because, as is clear from FIG. 2(C), the contact point Q2 between the hemming flange portion 1a and the inner panel 2 is located closer to the base portion ld than in the conventional case.

In this regard, conventionally, as is clear from FIG. 4, when applying the adhesive S in combination, the outflow of the adhesive S to the outside is regulated at the contact point Q between the inner panel 2 and the edge portion E; Since the adhesive S wraps around to the edge portion E, the amount of the adhesive flowing out to the outside increases, making post-treatment troublesome.

Effects of the Invention According to the present invention, the tip of the hemming flange at the end of the panel work is curved in a substantially arched shape in advance, and when the hemming flange is bent and overlapped with the mating panel, the top of the curved portion is Since the mating panel is brought into contact with the mating panel first, there is no sliding movement between the sharp edges and the mating panel, thereby preventing damage to the mating panel.

[Brief explanation of the drawing]

FIGS. 1(A), (B), (C), and (D) are the first embodiments of the present invention.
FIG. 2 (A), CB) is a process explanatory diagram showing an example of the process. (C) and (D) are process explanatory diagrams showing the second embodiment of the present invention, and FIGS.
The figure is a process explanatory diagram showing a conventional hemming method. l... Outer panel as a panel, 1a... Hemming flange part, ■b... Curved part, 1c... Top part, 2
Inner panel as the counterpart panel. Figure 1 (A)] Figure 1 (C) Figure 1 (B) Figure 1 (D)

Claims (1)

[Claims] (1) A method of hemming the end of a predetermined panel and hemming the panel to a mating panel, in which the tip of the hemming flange formed at the end of the panel is shaped in advance into a substantially arched shape. 1. A hemming method comprising: forming a hemming flange into a curve, and when folding the hemming flange portion to overlap with a mating panel, the top of the curved portion is first brought into contact with the mating panel.