JPH0798228B2 - Hemming method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hemming method for bending an edge portion of a steel plate panel constituting an automobile body, for example.

(Prior Art) An automobile body is formed of a large number of panels that are plastically processed into a predetermined shape, and most of these panels have an edge portion bent toward the back surface of the panel. For example, among the panels constituting an automobile panel, a door panel, a hood panel, a trunk lid panel, and the like are usually formed by an outer panel that is the outer surface of the vehicle body and an inner panel that is joined to the back surface of the outer panel. ing. In order to join the inner panel and the outer panel as described above, the flange of the inner panel is contacted with the flange formed on the edge of the inner panel, and the edge of the outer panel is connected to the flange of the inner panel. The outer panel is bent toward the back side until it touches. After the bending is completed, the edge portion of the outer panel and the flange portion of the inner panel are joined to each other by means such as an adhesive or spot welding.

The above-described bending of the edge portion is generally called hemming, and a hemming apparatus conventionally used for performing such hemming is shown in FIGS. 6 (A) to (C). There is something like that shown in.

As shown in the drawing, in the conventional pressing die for hemming, the lower die 1 is formed with the panel receiving portion 2 for supporting the inner panel Pi placed on the outer panel Po, and further the prehem blade. A rotating die 4 provided with 3 is attached to the lower die 1 so as to be rotatable around a pin 5. A pulling member is provided between the rotary mold 4 and the lower mold 1 to rotate the rotary mold 4 in the clockwise direction in the figure to apply an elastic force in a direction of separating the pre-ham blade 3 from the panel. The coil spring 6 is attached.

The upper die 7, which can move up and down above the lower die 1, is provided with a main hem blade 8 for bending the edge G of the outer panel Po, and is further provided in the rotating die 4. Ta roller 9
A drive cam 9 is provided on the upper mold 6 to abut on the upper mold 6 to rotate the rotary mold 4.

To perform panel bending using such a hemming press die, first, as shown in FIG. 6 (A), the outer panel Po of which the edge G is bent at a substantially right angle is used. Inner panel with flange F formed on top
The Pi is placed on the panel receiving portion 2 of the lower mold 1 in a state where the flange portion F is in contact with the back surface of the outer panel Po.

In this state, as shown in FIG. 6 (B), when the upper die 7 is lowered toward the lower die 1, the drive cam 10 comes into contact with the roller 9 and the prehem blade 3 causes the edge portion of the outer panel Po. G
Bend about 45 °. This processing is called prehem processing. Subsequently, when the upper die 7 descends, as shown in FIG. 6 (C), the prehem blade 3 separates from the panel, and the main hem blade 8 causes the edge G of the outer panel Po after the prehem processing is completed. Completely bend. This process is called clinching or hem processing. After the hemming process is completed in this way, the respective panels are welded by a spot welder or joined to each other by an adhesive previously applied between the panels before such a hemming process is performed. It

(Problems to be Solved by the Invention) When the edge portion of the panel is bent by the above-described conventional hemming device, so-called scraping may occur on the panel during the main hemming process, that is, the clinching process. It was This state is shown in FIG.
As shown in FIG. (A), the root of the edge G of the panel P is hard to bend due to work hardening during the main hemming process,
A bending moment M is generated and the surface of the panel P is separated from the panel receiving portion 2 of the lower mold 1. Panel P at this time
Is plastically deformed, as shown in FIG. 7 (B), even if the edge G is completely crushed, the scraped portion S is
I will remain.

In order to prevent the generation of the scrape S, as shown in FIG. 7 (C), a pad 11 is provided on the upper mold 6 and the inner panel Pi is pressed by the pad 11, or as shown in FIG. 7 (D). As described above, the flange portion F of the inner panel Pi may be pressed. However, when such a pad 11 is used, not only is there a problem that the inner panel Pi cannot be pushed too strongly, it is also impossible to provide the pad 11 so as to contact the entire circumference of the panel. However, there is a problem that only a part of the panel can be pressed.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to make it possible to perform the main hemming, that is, the clinching, without generating the shackle portion.

(Means for Solving the Problem) In order to achieve the above-mentioned object, the present invention provides the above-mentioned edge after bending the edge portion bent in advance at substantially right angles to the main body of the panel by a predetermined angle prehem processing. A hemming method for forming a main hem so that a portion thereof overlaps the main body of the panel, wherein a main hem blade having an edge for primary processing and an inclined surface continuous from this at the lower end is placed on the lower mold. After approaching toward the panel and pressing the edge tip of the panel by the edge for primary processing and bending until the tip comes into contact with the back surface of the panel, the inclined surface with the edge as the center It is a hemming method in which the main hem blade is rotated until it comes into contact with the outer surface of the edge portion and the edge portion is crushed so that the entire inner surface of the edge portion contacts the back surface of the panel.

(Operation) In the hemming method of the present invention, the edge formed on the tip of the present hem blade prevents the edge tip of the panel from being pressed and the root portion of the edge to be crushed. Bending is performed until the edge tips contact. After that, the hem blade rotates around the edge, and the inclined surface crushes the entire edge portion and the tip portion thereof is pressed by the edge. As a result, no bending moment is generated at the edge during the first bending process,
The panel will be surely hemmed without causing scraping.

(Example) Hereinafter, a hemming method of the present invention will be described in detail with reference to a hemig processing apparatus that embodies the method.

Above the lower mold 20 that supports the panel,
An outer slide 21 and an inner slide 22 that are vertically movable toward 20 are provided, and these slides 21 and 22 constitute an upper mold 23. A cam bracket 25 having an arc-shaped long hole 24 is fixed to the lower surface of the outer slide 21, and a hem block 27 having a main hem blade 26 at the lower end is fixed to the hem block 27 and fixed to each other. It is supported by the cam bracket 25 by penetrating the elongated hole 24 with two pins 28 which are separated by the distance.

An edge 30 for primary processing is formed at the lower end of the main hem blade 26, and an inclined surface 31 continuous from the edge 30 is further formed. The long hole 24 is formed so as to set the moving range of the main hem blade 26, that is, the hem block 27 around the edge 30, and the hem block 27 has a pin 28.
When the slides along the long hole 24, the main hem blade 26 moves so as to rotate around the edge 30.

Normally, a compression coil spring 33 is mounted between the hem block 27 and the spring bracket 32 fixed to the lower end of the outer slide 21 so that the pin 28 contacts the left end of the elongated hole 24. In this state, the hem blade
26 is almost vertical. A cam surface 34 is formed inside the hem block 27, and the inner slide 22 is provided with a drive cam 35 for melting the cam surface 34 to move the hem block 27. There is.

In order to bend the edge portion of the panel by using the above-described hemming device of the present invention, the outer panel Po and the inner panel Pi are placed on the lower mold 20, as shown in FIG. The edge portion G of the outer panel Po is bent at a substantially right angle to the main body portion of the outer panel Po, and the flange portion F is formed at the end portion of the inner panel Pi.

In this state, first, the edge G is bent at about 45 ° to perform prehem processing. This processing is indicated by reference numeral 39 in FIG.
Is performed by a prehem blade shown in FIG. 6, and this prehem blade 39 may be operated by utilizing the lowering movement of the upper die as shown in FIG.
Alternatively, driving means such as a hydraulic cylinder may be used.

After the prehem processing is completed as described above, the outer slide 21 is moved toward the lower mold 20, and the outer slide 21 is moved toward the lower mold 20, as shown in FIG.
As shown in FIG. 3, the edge 30 is pressed against the tip of the edge G, and the edge G is bent. When the bending process is completed, the tip of the edge portion G comes into contact with the back surface of the outer panel Po via the flange portion F of the inner panel Pi, as shown in FIG. 3 (A). .

The inner slide 22 descends together with the outer slide 21 when the outer slide 21 moves downward,
After the bending process is done by
When only 22 is lowered, as shown in FIG. 3 (B), the drive cam 35 comes into contact with the cam surface 34, and the hem block 27 rotates clockwise around the edge 30 of the hem blade 26. You will move as you would. This allows
The entire inner surface of the edge portion G is crushed so as to contact the back surface of the outer panel Po via the flange portion F of the inner panel Pi.

As described above, when the edge 30 presses the tip of the edge G and bends the edge G, no bending moment is generated in the edge G, so that the main body of the outer panel Pi has the structure shown in FIG. As shown in (A), the scrape does not occur.
In this way, with the tip of the edge G pressed by the edge 30, the edge G is pushed until it becomes horizontal by the inclined surface 31 formed continuously from the edge 30 at the tip of the hem blade 26. Crushed. In this process, the root of the edge G is deformed so as to be crushed while the tip of the edge G is pressed by the edge 30, so that the bending moment generated at this time propagates to other parts. Without the edge G
Bending is achieved.

FIG. 4 is a view showing another hemming device for carrying out the hemming process of the present invention, and the same members as those in the hemming device according to the above-mentioned embodiment are designated by the same reference numerals. In this case, unlike the case described above, the upper mold 23 is composed of one slide 21, and the hem block 27 is attached to the cam bracket 25 by the two pins 28a and 28b fixed thereto. . The cam bracket 25 is formed with elongated holes 24a, 24b through which the respective pins 28a, 28b penetrate and slide, and the inclination angles thereof are different from each other.

In addition, in this hemming processing device, the hem block
An inclined surface 37 that comes into contact with the roller 36 mounted on the 27 is provided on the cam bracket 25, and together with the slide 21 the lower die
The hem blade 26 that has approached to 20 presses the tip of the edge G at the edge 30 and bends this, and then the slide 21 continues to move toward the edge of the edge 30 to make a clock. Will rotate in the direction. This rotation is performed by contacting the roller 36 with the inclined surface 37.

FIG. 5 is a diagram showing another hemming apparatus embodying the hemming method of the present invention. In this case, unlike the case shown in FIG. 4, the case shown in FIGS. Same as outer slide 21 and inner slide 22.
The upper mold 23 has and. In this case, two parallel links 40, 41 and two other parallel links 42, 43 are connected to each other by four pins 44, which is a parallel movement mechanism.
The hem blade 26 is attached to the inner slide 22 by 45. This hem blade 26 and the inner slide 22
A tension coil spring 33a for maintaining the main hem blade 26 in a predetermined upright position is mounted between them. Also,
After the bending of the edge G of the outer panel Po is completed by the edge 30 of the book hem blade 26, a cam is provided on the outer slide 21 to rotate the book hem blade 26 about the edge 30. A drive cam 47 having a surface 46 is provided.

As described above, the hemming device shown in FIGS. 4 and 5 also performs bending by pressing the tip of the edge G of the panel Po, and pressing of the entire edge G. It will be crushed. In the hemming process of the present invention shown in the drawing, the edge of the outer panel Po is bent with the inner panel Pi placed on the panel Po. The present invention can be applied to the case where G is bent so that it directly contacts the back surface of the panel.

(Effects of the Invention) As described above, according to the present invention, the main hem blade having the edge for primary processing and the inclined surface continuous from this at the lower end is made to approach toward the panel placed on the lower mold. After pressing the edge edge of the panel with the edge for primary processing and bending until the edge comes into contact with the back surface of the panel, the inclined surface around the edge contacts the outer surface of the edge. Since the main hem blade is rotated until it comes into contact with the edge portion so that the entire inner surface of the edge portion comes into contact with the back surface of the panel, the edge portion is in a state in which the tip portion is pressed by the edge. As a result, the root portion is crushed, and the panel can be surely bent into a predetermined shape without causing scraping.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a hemming apparatus embodying the hemming method of the present invention, FIG. 2 is a right side view of FIG. 1, and FIGS. 3 (A) and (B) are FIG. 2 is a process diagram showing a processing procedure by the apparatus shown in FIG. 2, FIG. 4 is a sectional view showing another hemming apparatus embodying the hemming method of the present invention, and FIG. 5 shows still another hemming apparatus. Sectional views, FIGS. 6 (A) to 6 (C) are front views showing a hemming apparatus used in a conventional hemming method, and FIGS. 7 (A) to 7 (D) are panels according to the conventional hemming method. It is sectional drawing which shows the deformation | transformation state of. 20 …… Lower mold, 21 …… Outer slide, 22 …… Inner slide, 23 …… Upper mold, 26 …… Hem blade, 30 …… Edge, 31 …… Inclined surface, P …… Panel, P …… Outer panel, Pi …… Inner panel.

Claims (1)

[Claims] 1. A main hemming process in which an edge part that has been bent substantially at right angles to the main body part of the panel is bent by a pre-hem process at a predetermined angle and then the edge part overlaps the main body part of the panel. In the hemming method, the main hem blade having an edge for primary processing and an inclined surface continuous from this at the lower end is moved toward the panel mounted on the lower mold to move the edge for primary processing. After pressing the edge end of the panel by means of bending until the tip comes into contact with the back surface of the panel, the main hem blade is moved until the inclined surface comes into contact with the outer surface of the edge around the edge. A hemming method in which the edge is crushed so that the entire inner surface of the edge contacts the back surface of the panel by rotating.