JPH01249226A - Hemming method - Google Patents

Abstract

PURPOSE:To bend a hem part without generating recesses by approaching a main hem blade to a panel mounted on a lower die bending the tip of a panel hem part through an edge, then, squeezing the panel hem part rotating the main hem blade with the edge in the center. CONSTITUTION:An outer panel P0 and an inner panel Pi are mounted on a lower die 20. The hem part of the outer panel P0 is bent previously at right angles and a flange part F is formed on the edge part of the inner part Pi. Under this state, a hem part G is bent by a prehem blade to about 45 deg.. Then, an outer slide 21 approaches to the lower die 20 and bends the hem part G by the edge 30. At this time, the inner slide 22 lowers with the outer slide and after bending is executed by the edge 30, the inner slide 22 only lowers, a drive cam 35 comes in contact with a cam surface 34, the main hem blade 26 rotates in the clockwise direction centering the edge 30. Hereby, the hem part G is squeezed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a hemming method for bending the edge 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 worked into a predetermined shape, and many of these panels have edges bent toward the back surface of the panel. For example, among the panels that make up the automobile panel, door panels,
Hood panels, trunk lid panels, and the like are usually formed from an outer panel, which is the outer surface of the vehicle body, and an inner panel, which is joined to the back surface of the outer panel.

To join such an inner panel and an outer panel, the flange formed at the edge of the inner panel is in contact with the back surface of the outer panel, and the edge of the outer panel is connected to the flange of the inner panel. Bend it toward the back of the outer panel until it makes contact with the outer panel. After the bending is completed, the edge of the outer panel and the flange of the inner panel are joined to each other by adhesive, spot welding, or the like.

The above-mentioned edge bending process is generally referred to as hemming process, and the hemming process apparatus and equipment conventionally used to perform such hemming process are shown in FIGS. There are some as shown in C).

As shown in the figure, in the conventional press die for hemming, a lower die 1 is formed with a panel support portion 2 that supports an inner panel P1 placed on an outer panel po, and a pre-hemming press die is formed on the lower die 1. A rotary mold 4 provided with a blade 3 is attached to the lower mold 1 so as to be rotatable about a bin 5. A tension member is provided between the rotary mold 4 and the lower mold 1 to apply an elastic force in a direction in which the rotary mold 4 is rotated clockwise in the figure and the preham blade 3 is separated from the panel. A coil spring 6 is attached.

The upper mold 7, which can move up and down above the lower mold 1, has a main hem blade 8 for bending the edge G of the outer panel po.
Further, a drive cam 9 that contacts a roller 9 provided on the rotary mold 4 to rotate the rotary mold 4 is provided.
is provided on the upper mold 6.

To bend a panel using such a press die for hemming, first, as shown in FIG. 6(A), the outer panel po is bent at an almost right angle. The panel support of the lower mold 1 is placed on the part 2 with the inner panel Pi having a flange part F formed thereon, with the flange part F in contact with the back surface of the outer panel po.

In this state, when the upper mold 7 is lowered toward the lower mold 1 as shown in FIG. Bend G by approximately 45 degrees. This processing is called pre-hem processing.

Subsequently, when the upper mold 7 descends, as shown in FIG. 6(C), the pre-hem blade 3 separates from the panel, and the main hem blade 8 moves toward the outer panel Po after the pre-hem process.
The edge G of is completely bent. This processing is called clinch processing or real hem processing. After hemming has been completed in this way, each panel is either welded with a spot welder or bonded to each other with an adhesive previously applied between the panels before hemming. Joined.

(Problems to be Solved by the Invention) When the edges of a panel are bent using the conventional hemming device described above, so-called shackle may occur on the panel during the main hemming process, that is, clinching process. Ta. This state is shown in Figure 7.
As shown in Figure (A), during the main hemming process, the base of the edge G of the panel P is hardened due to work hardening and is difficult to bend.
A bending moment M is generated, and the surface of the panel P is separated from the panel support portion 2 of the lower mold 1. At this time, panel P
If it is plastically deformed, as shown in FIG. 7(B), even if the edge G is completely crushed, a shaky portion S will remain.

In order to prevent the occurrence of this shackle S, a pad 11 is provided on the upper die 6 as shown in FIG.
1 to hold the inner panel Pi, or press the inner panel Pi by pressing the
As shown in D), the flange portion F of the inner panel Pi
Sometimes it makes you feel like you're holding back. However, when such a pad 11 is used, there is not only a problem that the inner panel Pi cannot be pressed too strongly, but also it is impossible to provide the pad 11 so as to contact the entire circumference of the panel. However, there was a problem that only a part of the panel could be pressed.

The present invention has been made in view of the problems of the prior art described above, and it is an object of the present invention to enable the main hemming process, that is, the clinching process, to be performed without causing the shank portion.

(Means for Solving the Problems) In order to achieve the above object, the present invention involves bending the edges of the panel, which have been bent in advance at approximately right angles to the main body of the panel, by a pre-hem process at a predetermined angle, and then This is a hemming method in which the hemming is performed so that the edge overlaps the main body of the panel, and the hemming method includes: placing a hemming blade having a primary processing edge at the lower end and an inclined surface continuous from the edge on the lower die; After pressing the edge tip of the panel with the edge for primary processing and bending it until the edge abuts the back surface of the panel, In this hemming method, the main hemming blade is rotated until it comes into contact with the outer surface of the edge, and the edge is crushed so that the entire inner surface of the edge comes into contact with the back surface of the panel.

(Function) In the hemming method of the present invention, the edge formed at the tip of the hemming blade prevents the tip of the edge of the panel from being pressed and crushing the base of the edge, so that it can be attached to the back of the panel. The edges are bent until they touch. Thereafter, the main hem blade rotates around the edge, and its inclined surface crushes the entire edge while its tip is pressed by the edge. As a result, no bending moment is generated at the edge during the first bending process.
The hemming process will be performed reliably on the panel without causing any shading.

(Example) Hereinafter, the hemming method of the present invention will be described in detail based on a hemming device that embodies the method.

Above the lower mold 20 that supports the panel, outer slides 2 are respectively movable up and down toward the lower mold 20.
1 and an inner slide 22 are provided, and these slides 21 and 22 constitute an upper mold 23. A cam bracket 25 in which an arcuate long hole 24 is formed is fixed to the lower surface of the outer slide 21, and a hem block 27, which has a main hem blade 26 at its lower end, is fixed to the cam bracket 25 and mutually held in a predetermined position. The cam bracket 25 supports two bins 28 that are spaced apart from each other by passing through the elongated holes 24.

The lower end of the main hem blade 26 has an edge 30 for primary processing.
is formed, and a continuous slope 3 is formed from this edge 30.
1 is formed. The long hole 24 is connected to the edge 30.
The hem block 27 is formed so as to set the movement range of the main hem blade 26, that is, the hem block 27, with the via 28 sliding along the elongated hole 24.
The main hem blade 26 moves to rotate around this edge 30.

Normally, a compression coil spring 33 is installed between the spring bracket 32 fixed to the lower end of the outer slide 21 and the hem block 27 so that the spring bracket 728 contacts the left end of the elongated hole 24. In this state, the main hem blade 26 is in a substantially vertical state. A cam surface 34 is formed inside the hem block 27, and a drive cam 35 is provided on the inner slide 22 for moving the hem block 27 in contact with the cam surface 34. .

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

In this state, first, the edge G is bent by about 45 degrees, for example, and a pre-hem process is performed. This processing is performed by a pre-hem blade 39 shown in FIG. 1, and this pre-hem blade 39 is operated by utilizing the downward movement of the upper mold, as shown in FIG. Alternatively, a driving means such as a hydraulic cylinder may be used.

After the pre-hem processing is completed as described above, the outer slide 21 is brought closer to the lower die 20, and as shown in FIG.
As shown in A), the edge 30 is pressed against the tip of the edge G, thereby bending the edge G. When this bending process is completed, the tip of the edge G is shown in FIG.
As shown in A>, the inner panel Pi comes into contact with the back surface of the outer panel po via the flange portion F.

The inner slide 22 is similar to the outer slide 2.
When the inner slide 22 moves downward, the drive cam 35 moves downward together with the inner slide 22, and after the bending process is performed by the edge 30, only the inner slide 22 descends, as shown in FIG. 3(B). comes into contact with the cam surface 34, and the hem block 27 moves so that the main hem blade 26 rotates clockwise about the edge 30. As a result, the entire inner surface of the edge G is crushed so as to come into contact with 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 the main body of the outer panel P1 has a As shown in (A), the shackle does not occur. With the edge 30 pressing the tip of the edge G in this manner, the edge G is pushed up by the inclined surface 31 formed continuously from the edge 30 at the tip of the main hem blade 26 until it becomes horizontal. crushed. In this process, the tip of the edge G is pressed by the edge 30 and the base of the edge G is deformed so as to be submerged, so the bending moment generated at this time is propagated to other parts. The bending of the edge G is achieved without any bending.

FIG. 4 is a diagram showing another hemming device for performing the hemming process of the present invention, and the same reference numerals are given to the same members as those in the hemming device according to the embodiment described above. In this case, unlike the case described above, the upper mold 23 is composed of one slide 21, and k
Mudalock 2F has two pins 28a fixed thereto,
It is attached to the cam bracket 25 by 28b.

The cam bracket 25 has the respective pins 28a.
, 28b are formed through which elongated holes 24a and 24b slide, and these have different inclination angles.

Further, in this hemming processing device, the cam bracket 25 is provided with an inclined surface 37 that contacts the roller 36 attached to the hem block 27, and the slide 21
The main hem blade 26, which has approached the lower die 20 at the same time, presses the tip of the partial edge G of the edge 30 and bends it. It will rotate clockwise around the center. This rotation is achieved by the inclined surface 37 coming into contact with the roller 36.

FIG. 5 is a diagram showing another hemming device embodying the hemming method of the present invention, and in this case, the case is different from that shown in FIG. 4, and the case shown in FIGS. Similarly, the upper mold 23 has an outer slide 21 and an inner slide 22. In this case, two parallel links 40.41 and two other parallel links 42.
43 are mutually connected by four pins 44, the inner slide 22
A main hem blade 26 is attached to the main hem blade 26. This book hem blade 26
and the inner slide 22, the main hem blade 2
A tension coil spring 33a is attached to maintain the device 6 in a predetermined upright position. Further, after the bending process of the edge G of the outer panel po is completed by the edge 3o of this main hem blade 26, in order to rotate the main hem blade 26 around this edge 30, the outer slide 2
1 is provided with a drive cam 47 having a cam surface 46.

The hemming device shown in FIGS. 4 and 5 described above can also perform bending by pressing the tip of the edge G of the panel PO, and pressing the entire edge G. A crushing process will be performed. In the illustrated hemming process of the present invention, the edge of the outer panel po is bent with the inner panel Pi placed on top of the panel PO, but the edge of one panel It is also possible to apply the invention when the G is bent so that it is in direct contact with the back side of the panel.

(Effects of the Invention) As described above, according to the present invention, the present hem blade having the edge for primary processing at the lower end and the sloped surface continuous from the edge is moved toward the panel placed on the lower mold. After pressing the edge tip of the panel with the edge for primary processing and bending it until the tip abuts the back surface of the panel, the inclined surface about the edge comes into contact with the outer surface of the edge. The main hem blade was rotated until the edges came into contact with each other, and the edges were crushed so that the entire inner surface of the edges came into contact with the back surface of the panel, so that the tip of the edge was pressed down by the edge. As a result, the base portion is crushed, and the panel can be reliably bent into a predetermined shape without causing any shackle.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a hemming device embodying the hemming method of the present invention, FIG. 2 is a right side view of FIG. 1, and FIGS. FIG. 2 is a process diagram showing the processing procedure using the apparatus shown in FIG. 4, a sectional view showing another hemming device embodying the hemming method of the present invention, and FIG. 5 showing still another hemming device. 6(A) to 6(C) are front views showing a hemming device used in the conventional hemming method, and FIGS. 7(A) to 7(D) are panels obtained by the conventional hemming method. It is a sectional view showing a deformed state. 20... Lower die, 21... Outer slide, 22...
... Inner slide, 23 ... Upper die, 26 ... Main hem blade, 30 ... Edge, 31 ... Inclined surface, P ...
・Panel, P...outer panel, Pi...inner panel. Patent applicant Nissan Motor Co., Ltd. agent Patent attorney 8 1) Mikio (and 1 other person) (B) Figure 7 (A)
(B) (C) (D)

Claims (1)

[Claims] A hemming method in which an edge that has been bent in advance at a substantially right angle to the main body of the panel is bent by pre-hem processing at a predetermined angle, and then a permanent hem is processed so that the edge overlaps the main body of the panel. The main hem blade, which has an edge for primary processing at the lower end and an inclined surface continuous from the edge, is brought close to the panel placed on the lower die, and the edge of the panel is cut by the edge for primary processing. After pressing the tip and bending it until the tip abuts the back surface of the panel, rotate the main hem blade around the edge until the inclined surface abuts the outer surface of the edge. A hemming method in which the edge is crushed so that the entire inner surface of the edge comes into contact with the back surface of the panel.