JPH06344038A - Vibration hemming process - Google Patents

Abstract

PURPOSE:To improve hemming process a place like a corner part where the preliminary bending is not well carried out and the real bending is impossible. CONSTITUTION:In a hemming process that an outer panel 1 and an inner panel 2 are superposed, and both 1, 2 are joined by bending back the periphery of the outer panel 1 and holding the periphery of the inner panel 2 between the aboves, a forming blade 3 is put on the upper end of the hem flange 1a formed on the periphery of the outer panel 1 by a prescribed angle and fed while applying a micro-vibration onto this forming blade 3. Then, the end of the hem flange 1a is pressed and bent with a conventional hemming press 4, and the peripheral part of the inner panel 2 is held.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention folds a hem flange provided at an edge of one metal plate of two superposed metal plates and folds it over the edge of the other metal plate to join them. The present invention relates to a hemming process, and can be used, for example, for joining an outer panel and an inner panel in an outer panel body of an automobile.

[0002]

2. Description of the Related Art In outer panel bodies such as hoods, fenders, side doors, luggage doors, etc. that compose an automobile body, a hem flange formed on the edge of the outer panel is folded back, and the edge of the inner panel is clamped by the folded hem flange. The two panels are thus joined together. This type of processing method is generally called hemming, and as shown in FIG. 3, a hem flange (11a) that rises at a right angle is formed in advance on the edge of the outer panel (11), and the hem flange (11a) is formed in advance. With the edge of the inner panel (12) superposed on the inside of the, the hem flange (11a) is first bent by the preliminary bending blade (13) to a predetermined angle, and then the final bending is performed by the main bending blade (14). I am trying.

However, in the hemming process, the following problems often occur at the corner portions other than the straight portions. That is, when the hem flange (11a) is bent toward the edge portion of the inner panel (12) at the corner portion, inevitably a surplus of meat is generated, and this surplus of meat causes a large number of wrinkles. The generation of wrinkles not only impairs the appearance but also causes a part of the wrinkles to protrude from the corner portion in a protruding shape, which may cause a safety problem. Furthermore, the outer surface of the outer panel (11) may be deformed.

Therefore, conventionally, as shown in FIG. 4, by removing the hem flange (11a) at the corner portion and making the flange dimension (S1) extremely shorter than the flange dimension (S2) of the straight portion, In addition to reducing the excess thickness of the corner portion, as shown in FIG. 5, at the corner portion, the processing is stopped at the pre-bending stage and the main bending is not performed.

[0005]

According to the above-mentioned conventional method, wrinkles can be prevented from being generated in the corner portion, but the gap between the corner portion and the inner panel caused by not performing the main bending is used as the sealant. Special consideration such as filling with paint or paint is required separately. This increases the number of processes and is something that we want to avoid.

Generally, an ideal hemming shape required for a corner portion is to connect a hemming portion of a straight line portion with a more natural shape while maintaining a large R so as not to cause wrinkles, as shown in FIG. For this purpose, it is necessary to bend while maintaining a large radius in the central portion of the upright hemming flange, which is difficult only by unidirectional pressing unless there is a backup type from the inside. However, it is actually difficult to insert a backup mold, and if not, a bent wrinkle will be created from the flange bending root. For this reason, the current state is that hemming processing is not performed on this portion.

Therefore, an object of the present invention is to improve the hemming process where the pre-bending such as the above-mentioned corner portion is not successful and the main bending cannot be performed.

[0008]

According to the method for vibrating hemming according to the present invention, two plate materials are overlapped with each other and the edge portion of one plate material is folded back to sandwich the edge portion of the other plate material. In the hemming method for joining plate members, the upper end of the hem flange formed at the edge of the one plate member, a shaping blade is applied at a predetermined angle, and feeding is performed while applying minute vibration to this shaping blade. To do.

[0009]

The function of hemming the flange portion with a forming blade having fine vibration is similar to that of a skilled worker of fine sheet metal working to form a shape by using a small hammer and a large number of hammers. That is, continuous microplastic deformation is performed by making a forming blade with appropriate mass and speed collide with the upright hemming flange many times, and the material of the hem flange repeats fine plastic deformation to cause wrinkles and distortion. Leads to the formation of less rope hem.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment will be described below with reference to the drawings.

1 (a), (b) and (c) show each process of hemming. First, two plate materials, that is, an outer panel (1) and an inner panel (2) are placed in an overlapping manner as shown in FIG. An upright hem flange (1a) is formed in advance on the edge of the outer panel (1).
Next, the end of the hem flange (1a) of the outer panel (1) is contacted with a forming blade (3) that performs micro-vibration at a constant angle (θ), and the forming blade (3) is indicated by a white arrow. By feeding in the direction shown, the tip of the hem flange (1a) is gradually bent as shown in FIG. 1 (b).
In the final step shown in FIG. 1 (c), the tip of the hem flange (1a) is pushed and bent by a normal hemming press (4) to clamp the edge of the inner panel (2) (main hem step).

In order to apply vibration to the forming blade (3), it is necessary to appropriately select and employ a mechanical actuator, a pneumatic coil type actuator, a voice coil type actuator, an electromagnetic solenoid or other driving means. it can.

The mass of the forming blade, the shape of the forming blade, the angle of the forming blade, the position at which the forming blade is applied, the frequency of the vibration of the forming blade, the amplitude, the feed, etc. are determined by the dimensions of the hem flange, the material of the plate material, and the hemming process. The optimum value should be set in consideration of whether the position to be applied is a linear part or a corner part.

[0014]

As described above, according to the present invention, the two plate members are combined by stacking the two plate members, folding back the edge of one plate member, and sandwiching the edge of the other plate member. In the hemming method, the upper edge of the hem flange formed on the edge of the one plate member is contacted with a molding blade at a predetermined angle, and the molding blade is fed while giving a slight vibration. The material of the hem flange repeatedly undergoes fine plastic deformation, and it becomes possible to perform hemming processing with less wrinkles and distortion even at the corners.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing each step of a vibration hemming method.

FIG. 2 is a partial perspective view of works joined by a vibration hemming method.

FIG. 3 is a schematic diagram showing each step of a conventional hemming method.

FIG. 4 is a perspective view (a) and a sectional view (b) of an outer panel for explaining a conventional technique.

FIG. 5 is a sectional view for explaining a conventional technique.

[Explanation of symbols]

 1 Outer panel 1a Hem flange 2 Inner panel 3 Vibration forming blade

Claims (4)

[Claims] 1. A hemming method in which two plate materials are overlapped with each other, and an edge portion of one plate material is folded back and an edge portion of the other plate material is sandwiched so that the two plate materials are joined to each other. A vibrating hemming method, characterized in that a forming blade is applied to an upper end portion of a hem flange formed at an edge of the forming blade at a predetermined angle, and the forming blade is fed while giving a slight vibration. 2. A hemming method for joining an outer panel and an inner panel by stacking the outer panel and the inner panel, folding back the edge of the outer panel and sandwiching the edge of the inner panel, and forming the outer panel and the inner panel at the edge of the outer panel. A method for vibrating hemming, characterized in that a forming blade is applied to an upper end portion of a hem flange at a predetermined angle, and the forming blade is fed with a minute vibration. 3. A rope hem is formed by contacting a corner of a hem flange of a corner portion with a forming blade, which has been subjected to minute vibration, while feeding, and repeatedly applying minute plastic deformation to the edge of the flange. Characteristic vibration hemming method. 4. The vibration hemming method according to claim 1, 2 or 3, wherein after the processing by the forming blade, the end portion of the hem flange is subjected to main bending processing by a press.