JPH01249222A - Hemming method for metallic sheet - 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 hemming a metal plate.

(Prior art) Conventionally, the hemming method using a roller was disclosed in Japanese Patent Application Laid-open No. 61-2.
As seen in Publication No. 62432, after performing flange bending in which the end of the metal plate is vertically bent, a pre-hem roller performs preliminary bending in which it is bent diagonally by rolling pressure from one side of the flange portion, and then a hem roller There is a known method that performs main bending, in which the material is rolled and bent flat. In hemming by this method, the bending stress of the pre-hem roller P is applied only from one direction indicated by the arrow in FIG. 6 during pre-bending, and springback may occur in the pre-bending corner Q. For this reason, unnecessary warping R occurs in the portion other than the pre-bending corner Q, and the pre-bending may take the shape shown by the imaginary line. For this reason, after the final bending by the hem roller, the bent end S may lift as shown in FIG.

In addition, if the rolling direction of the pre-hem roller needs to be changed because the pre-bending corner extends in a curved line rather than a straight line, the bending stress of the pre-hem roller is not constant and changes. As a result, the preliminary bending may not be performed uniformly.

This affected the subsequent final bending, making it difficult to bend into a predetermined flat shape.

(Problems to be Solved) In order to solve this problem, the present invention provides a method for bending a metal plate by flange bending, and then, as a pre-process of the main bending, the pre-bending corner extends not only in a straight line but also in a curved shape. To provide a method for hemming a metal plate, which can perform preliminary bending by bending the pre-bent corner to an acute angle even when the metal plate changes and extends, and can be bent into a predetermined shape in the subsequent main bending. It is.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a step of bending a flange to raise the end of a metal plate, and a step of bending a press roller at a pre-bending corner of one side of the flange. A pre-hem roller is brought into contact with the pre-bent surface portion of the other side of the flange portion which is in contact with the sharp edge of the outer periphery and which faces the press roller, and both rollers are moved together along the flange so as to be diagonal. This method is characterized by comprising a step of performing preliminary bending, and a step of performing main bending, in which the preliminary bent portion is further pressed and bent.

(Function) In such a means, after the flange bending is performed, the pre-hem roller moves while pressing and bending the flange portion using the inside of the flange portion, which is in pressure contact with the edge of the press roller, as a fulcrum.

At this time, since the pressing roller presses the bending corner of the pre-bending, the bending stress from the pre-hem roller is suppressed from affecting parts other than the pre-bending corner, and the pre-bending angle Allows the section to be bent at an acute angle.

After performing the preliminary bending as described above, it is possible to further bend the material into a predetermined shape by applying pressure during the final bending.

(Example) An example of implementing the present invention will be described below with reference to FIGS. 1 and 2.

In FIG. 1, reference numeral 1 indicates the press roller having an acute edge on the outer periphery, and 2 indicates a pre-hem roller having the same shape as the press roller.

Further, A indicates the outer plate subjected to flange bending, B indicates the flange portion, C indicates the preliminary bending corner portion, and D indicates the preliminary bending surface portion.

Furthermore, the line along the pre-bent corner C of the outer plate A changes into a gentle curve.

The pressing roller l is provided at the tip of the rotating shaft 3,
The pre-hem roller 2 has an arm 5 that supports a rotating shaft 4.
It is provided at the tip of the

The outer plate A is placed on top of the inner plate F with the flange bent corner E touching the stepped portion 7 provided on the hemming die 6.

The outer circumferential edge of the press roller 1 is brought into contact with the pre-bent corner C of the outer plate A, and the outer circumferential edge of the pre-hem roller 2 is brought into contact with the pre-bent surface.

Thereafter, both rollers 1 and 2 are moved horizontally along the flange portion B while simultaneously applying pressure from both sides.

Thereby, even if the line along the pre-bending corner C changed into a curved line, it could be bent at an acute angle.

Next, as shown in the second figure, the flange part B of the outer plate A after preliminary bending was pressed with a punch 8 to finally bend it, thereby making it possible to hem the main bent corner part G flatly.

Next, other embodiments will be described using FIGS. 3 to 5.

In FIG. 3, 9 indicates a press roller and IO indicates a pre-hem roller.

The press roller 9 is provided at the tip of the rotating shaft 11, the pre-hem roller 10 is provided at an intermediate position of the rotating shaft 12, and the rotating shafts 11 and 12 are arranged in parallel with the roller holder 13.

After the outer plate H is flanged at the end, it is placed on the hemming die 14 overlapping the inner plate I, and the flange J of the outer plate H is pressed from both sides with a pressing roller 9 and a pre-hem roller IO.
are pressed into contact with each other.

At this time, the sharp edge of the outer periphery of the pressing roller 9 presses the intermediate position of the flange portion J.

Thereafter, the roller holder 13 is attached to the flange portion J.
By horizontally moving the flange in the direction indicated by the arrow in FIG. 4 along the flange bending corner, it was possible to perform preliminary bending with the middle of the flange J at the upper position as the preliminary bending corner L.

Next, as shown in FIG. 5, the flange portion J of the outer plate H after preliminary bending is pressed by the bunches 15 and fully beveled, thereby forming a shape having a fully beveled corner portion M in the middle of the flange portion J. was completed.

As described above, this method can also be adopted when setting a pre-bending corner in a position different from the flange-bent corner of a shell plate that has undergone flange bending.According to this embodiment, the flange can be appropriately After determining the bending corner, it is possible to hem it into the required shape by cutting the main surface.

(Effect) Therefore, according to the present invention, after the edge portion of the metal plate is flange-bent, the pressing roller presses the pre-bending corner portion along the flange portion. A preliminary method that can prevent deformation due to unnecessary stress, and even when the pre-bent corner extends not only in a straight line but also in a curved manner, the pre-bent corner is uniformly bent to an acute angle. Can be bent.

Furthermore, even when the preliminary bending corner is set at a different position from the flange bending corner, preliminary bending can be easily performed.

Therefore, it is possible to provide a method for hemming a metal plate that can be bent into a predetermined shape by subsequent hoisting.

[Brief explanation of the drawing]

FIG. 1 is an explanatory sectional view showing a preliminary bending process in an embodiment of the present invention, FIG. 2 is an explanatory sectional view showing a final bending process in an embodiment of the present invention, and FIG. FIG. 4 is an explanatory cross-sectional view showing a preliminary bending process in another embodiment of the present invention, FIG. 4 is a cross-sectional view taken along line a-a in FIG. 3, and FIG. 6 is a sectional view showing a preliminary bending step by a conventional method, and FIG. 7 is a sectional view after completion of hemming by a conventional method. 1.9... Holding roller 2.10... Pre-hem roller B... Flange portion C... Preliminary bending corner portion D... Preliminary bending surface portion Fig. 1 Fig. 2 Fig. 7

Claims (1)

[Claims] 1. The step of flange bending to raise the end of the metal plate, and the step of contacting the sharp edge of the outer periphery of the press roller with the pre-bent corner of one side of the flange portion, and the step of bending the metal plate facing the press roller. A step of press-contacting a pre-hem roller to a pre-bending surface portion on the other side of the flange portion, and performing pre-bending by rolling both rollers together along the flange to bend the pre-bending portion diagonally; and further pressing the pre-bending portion. A method for hemming a metal plate, comprising a step of final bending.