JPS61195839A - Method of treating tabular end section with laminated flitch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for treating the edges of a board having a laminated plywood, and particularly to a method for treating the edges of a board having a laminated plywood, and in particular, a method for treating the edges of a board having a laminated plywood. The present invention relates to an edge treatment method for joining an edge of plywood and an edge of a metal plate.

(Prior art) Conventionally, for automobile bodies, etc., laminated plywood, which is made by laminating thin metal plates on both surfaces of a synthetic resin intermediate layer, has been used to reduce weight and absorb vibrations. I came.

When assembling the panel structure by using the above laminated plywood as the outer panel of a panel structure such as an automobile door and using a metal plate as the inner panel, and joining the ends of the laminated plywood and the end of the metal plate, the third Laminated plywood 102 as shown in figure (a)
The end portion 102A of is folded back and hemmed, as shown in FIG.
Laminated plywood 102 and metal plate 1 are bonded by spot welding as shown in
03, the following problem occurs.

The thickness of the metal plate 103 is approximately 1.0 mm, which is very thin, so the curvature of the bent portion 104 of the laminated plywood 102 becomes extremely large, and the thin metal plate on the outer surface side of the bent portion 104 is torn. There are problems such as the heat during welding being transmitted to the outer surface of the laminated plywood 102 through the metal plate 103, deforming the thin metal plate on the outer surface side, and deteriorating the appearance of the outer panel.

Therefore, for example, in Japanese Utility Model Application Publication No. 57-125321,
The end of one thin metal plate of the laminated plywood is made to protrude beyond the end surface of the other thin metal plate, and the protruding portion is folded back and hemmed to weld the end of the laminated plywood and the metal plate. A bonding edge treatment technique is described.

However, the edge processing technology described in the above publication has a structure in which only one thin metal plate of the laminated plywood is folded back and hemmed, which is not desirable in terms of the strength of the joint, and the overall thickness of the joint is Because of the smaller size, the thin metal plates on the outer side of the laminated plywood will be deformed by thermal distortion during welding, deteriorating the appearance, and the end faces of the two thin metal plates of the laminated plywood should be processed so that they are shifted rather than aligned. However, there are problems such as equipment and process difficulties.

(Object of the Invention) The present invention has been made in view of the above-mentioned problems, and it is a laminated plywood that can prevent tearing of the thin metal plate at the bending part of the laminated plywood and deformation of the thin metal plate on the outer surface of the laminated plywood. It is an object of the present invention to provide a method for treating the edges of a board including plywood.

(Structure of the Invention) A method for treating the edges of a board including laminated plywood according to the present invention includes:
The ends of the laminated plywood as the outer panel, which is made by laminating thin metal plates on both surfaces of a synthetic resin intermediate layer, are bent inward into a flange shape, and the ends of the metal plate as the inner panel are folded into the folded parts of the laminated plywood. Bend the laminated plywood toward the inner surface with a smaller curvature than the curvature, overlap the metal plate on the inner surface of the laminated plywood, and weld and join the edge of the laminated plywood and the edge of the metal plate to form a bond between the edge of the laminated plywood and the metal plate. The ends of the metal plate are folded back onto the inner surface of the metal plate and hemmed.

(Effects of the Invention) In the method for treating the edges of a plate material equipped with a laminated plywood according to the present invention, the end of the laminated plywood is bent inward into a flange shape, and the end of the metal plate is adjusted to the curvature of the bent portion of the laminated plywood. It is bent inward with a smaller curvature than the curvature, welded together the edge of the laminated plywood and the edge of the metal plate, and then folded back and hemmed. Since the distance to the unbent outer edge of the laminated plywood becomes longer, deformation due to thermal distortion of the thin metal plate at the outer edge of the laminated plywood can be prevented.

When the parts near the edges are welded together and then folded back, the curvature of the bent part of the laminated plywood and the curvature of the end of the metal plate are set to be approximately equal, and the ends of the two are overlapped. If the laminated plywood is combined and folded back, there is a risk that the tensile stress at the bent portion of the laminated plywood will become excessive and the outer thin metal plate will break. Since the bending curvature of the metal plate is set small, it is possible to reliably prevent tensile stress other than bending stress from acting on the bent part of the laminated plywood, and the end of the laminated plywood is folded back with two metal plates in between. The hemming bending curvature also becomes smaller and the bending stress is alleviated.

In this way, it is possible to reliably prevent the thin metal plate on the outer surface side of the bent portion of the laminated plywood from being torn or distorted.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

For example, as an outer panel of a panel structure 1 consisting of an outer panel and an inner panel such as a car door, a synthetic resin intermediate layer 2a is coated on both surfaces with a thickness of approximately 0.1 to 0.
A laminated plywood 2 made of laminated thin plates 2b of about 4.0 mm thick is used, and a steel plate 3 with a thickness of about 0.8 to 1.2 mm is used as an inner panel, and the ends of the laminated plywood 2 and the steel plate 3 are used as inner panels. The panel structure 1 is assembled by joining the ends of the panels through the following steps.

First, as shown in FIG. 1(a), 1. The end portion 2A of the laminated plywood 2 is bent inward by press working into a flange shape at approximately 90°, and the end portion 3A of the steel plate 3 is press worked to reduce the curvature (1/
The steel plate 3 is bent on the inner surface of the laminated plywood 2 with a smaller curvature (1/R) than r), and the laminated plate F
The near edge portion 2B of i2 and the near edge portion 3B of the steel plate 3 are overlapped, and the near end portion 3C of the steel plate 3 is overlapped with the laminated plywood 2.
overlap the outer end 2C of.

In this state, a somewhat large gap 5 is left between the inner surface of the bent portion 4 of the laminated plywood 2 and its vicinity, and the outer surface of the end portion 3A of the steel plate 3, as shown in the figure.
The length of the girth along the steel plate 3 in the gap 5 is longer by a predetermined amount than the length of the girth along the laminated plywood 2 .

Next, as shown in FIG. 1(b), the movable electrode 6a of the spot welding machine is applied to the outside of the edge area 2B of the laminated plywood 2, and the movable electrode 6a of the spot welding machine is applied to the inner side of the edge area 3B of the steel plate 3. The fixed side electrode 6b is applied and heated to soften the synthetic resin intermediate layer 2a of the laminated plywood 2, and then electricity is applied between the electrodes 6a and 6b to weld and join the above-mentioned edge portions 2B and 3B together.

Finally, as shown in FIG. 1(c), the end 2A of the laminated plywood 2 and the end 3A of the steel plate 3 are pressed into the rope plate 3 using a press machine.
Fold back onto the inner surface of the hem.

At this time, the laminated plywood 2 is bent at the bending part 4, and the steel plate 3 is bent at the part of the laminated plywood 2 closest to the bending part 4.

Here, the relationship between the bending radius r of the bent portion 4 of the laminated plywood 2 and the curved bending radius R of the end portion 3A of the steel plate 3 can be theoretically determined as follows.

That is, the thickness of the steel plate 3 is tl, and the total thickness of the laminated plywood 2 is t2.
, if the distance between the center of curvature of the hemming bend and the inner end of the welded joint 7 is B as shown in FIG. 1(C), and the distance between the centers of curvature is A as shown in FIG. 1(b), , the following equation is obtained.

A=(R-r)+(tl+t2)/2 1) 2B+
t lxπ/2=RXπ/2 (2) 2B
+ (tl+t2/2)xπ =2A+rXπ/2 (3) Above (1
) (21 (If A and B are eliminated from equation 31, the following equation is obtained.

(R-r) = (tl + t2) If it is set so that the above formula (4) is satisfied, the laminated plywood 2 can be bent without any tension acting on the laminated plywood 2 when it is folded and hemmed as shown in Fig. 1(c). become.

In the above-mentioned edge treatment method, before hemming, the area near the edge of the laminated plywood 2 2BC! : Near edge portion 3B of rope plate 3
Since the parts are welded together, the laminated plywood 2 is removed from the welded part during welding.
The distance from the outer end 2C to the outer end 2C becomes longer.
C is not deformed by welding heat.

In addition, when the parts 2B and 3B near both end edges are welded together and then folded back and hemmed, if the above R>r is set and R and rJr are set to values that satisfy equation (4), when folded and hemmed. No tension is applied to the laminated plywood 2 during this period.

Furthermore, since the end portion 3A of the steel plate 3 is also folded back and sandwiched between the end portions 2A and 2C of the laminated plywood 2, the hemming bending curvature of the laminated plywood 2 is also reduced, and no adverse effects of bending stress appear.

It goes without saying that the end portion 3A of the steel plate 3 may be bent to have a polygonal cross section as shown in FIG.

[Brief explanation of the drawing]

1 and 2 of the drawings show an embodiment of the present invention, and FIGS. 1(a) to 1(c) show the end portions of the laminated plywood and the steel plate joined together. A vertical cross section of the main part at each stage of processing, FIG. 2 is a vertical cross section of the end of the steel plate according to a modified example,
Figures 3(a) and 3(b) are related to the prior art, and are a vertical cross-sectional view of a portion of a laminated plywood hemmed to a metal plate, and a longitudinal cross-sectional view showing a state in which the laminated plywood is hemmed to a metal plate and welded, respectively. be. 2. Laminated plywood, 2a. Synthetic resin intermediate layer, 2b.
・Thin steel plate, 2A...end, 2B...near edge,
3... Steel plate, 3A... Edge, 3B... Near edge.

Claims (1)

[Claims] (1) The ends of the laminated plywood as the outer panel, which is made by laminating thin metal plates on both surfaces of a synthetic resin intermediate layer, are bent toward the inner cylinder side into a flange shape, and the ends of the metal plates as the inner panel are folded into the laminated plywood. Bend it toward the inside with a curvature smaller than the curvature of the bent part of A method for treating the edges of a plate material with laminated plywood, characterized by folding the end portion of the metal plate back onto the inner surface of the metal plate and hemming the end portion of the metal plate.