JP3390479B2 - Hemming equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hemming method applied to a work made of a material having a small elongation such as an aluminum-based material. 2. Description of the Related Art Conventionally, various products have been hemmed. For example, in a vehicle door, an edge of an outer panel of the door is hemmed so as to surround an edge of an inner member. By the way, recently, doors in which an outer panel and an inner panel are formed of an aluminum-based material have been manufactured. In this case, it is necessary to make the panel thickness relatively large in order to secure strength.
When hemming is performed with a large curvature, the elongation of the outer surface becomes larger than an allowable limit, so that rough skin and minute cracks are easily generated. Furthermore, in order to hemming working with large curvature, by applying strong pressure on the inside over the edge of the outer panel in the pre-hemming step in a predetermined folding line, the panel edge from folding line must bending inward at an acute angle However, in this case, as shown by the imaginary line in FIG. 3, the panel a is bent by receiving the thrust force F, and a so-called shark is generated. Therefore, in the aluminum door, a rope hem as shown in FIG. 4 is employed, and the edge of the outer panel a is hemmed with a relatively small curvature. In the above-mentioned rope hem, since the curvature of the hemming process is small , the edge of the door becomes thick and the appearance is deteriorated. In view of the above points, hemming a workpiece formed of a material having small elongation of aluminum-based material or the like, rough skin and fine cracks further that adapted to hemming by without large curvature produces Shakure Its purpose is to provide a device . [0004] In order to achieve the above object,
The present invention provides a work receiver, a pre-hemming edge,
The heating edge is heated by heating means to
Pre-hemming and book while heating
Hemming processing equipment that performs hemming processing consisting of hemming
The work receiver is erected in a lower mold,
A swing frame with a hemming edge erected on the lower mold so as to freely swing
When the hemming edge is suspended from the upper mold,
Then, the hemming edge is inclined downward toward the outside.
Between the upper die and the swing frame.
The swing frame is swung to the processing position by the descent operation of
A second cam for retracting the first cam and the swing frame from the processing position.
A driver cam having a
Near pre-hemming edge and hemming edge machining area
A heating means is provided on each side . When the work is heated to a warm region, the extensibility of the work is improved, and even if the work is hemmed with a large curvature, the surface of the work is not roughened or fine cracks are generated on the outer surface thereof, and shaking does not occur. do not do. When the work is made of an aluminum-based material, it is possible to heat the work up to 400 to 500 ° C., but it is desirable to set the heating temperature to about 200 ° C., since the heat causes adverse effects such as a change in structure. FIG. 1 shows a hemming type in which an edge of an outer panel a formed of an aluminum-based material constituting a vehicle door is hemmed so as to surround an edge of an inner member b.
Is shown. The hemming type of the device includes a work receiver 2 erected on a lower die 1, a swing frame 3 erected on the lower die 1 so as to be swingable about a shaft 3a, and a swing frame. 3, a pre-hemming edge 4 fixedly mounted on the upper die 5, a hemming edge 6 vertically mounted on an upper die 5 to be moved up and down, and a driver cam 7 vertically mounted on the upper die 5. A first cam 7a that swings the swing frame 3 inward in cooperation with the protrusion 3b formed on the outer surface of the frame 3, and swings in cooperation with a pin 3c provided horizontally on the swing frame 3. Second cam 7 that swings frame 3 outward
b was fixed. The edge of the outer panel a is bent at a substantially right angle in the previous step, and the outer panel a is placed on the work receiver 2 with the inner member b superposed thereon, and then the upper die 5 is lowered. Hemming was performed. At this time, the swing frame 3 is first swung inward by the first cam 7a, the preheming edge 4 abuts against the edge of the outer panel a, and the edge is bent obliquely inward. The swing frame 3 is swung outward by the 2 cam 7b, the pre-hemming edge 4 is retreated outward, and subsequently the hemming edge 6 is moved to the outer panel a.
Abutting the edge from above, and the edge is completely bent downward, thereby completing the hemming process. Here, the outer edge of the lower end of the hemming edge 6 is inclined downward outward as shown in FIG. 2, so that the edge of the outer panel a is hemmed at an acute angle. . As a result, the end of the door is clear and the appearance is improved. However, since the outer panel a is formed of a relatively thick and small-elongation aluminum-based material, if the hemming is simply performed, the outer panel a is located outside the hemmed portion. Rough skin and minute cracks occur on the surface. Therefore, in this embodiment, the work receiver 2, the pre-heming edge 4 and the hemming edge 6, which are the hemming-type work abutting portions, are heated by a heating means 8 such as an electric heater embedded therein to form a work outer panel. The hemming process was performed while heating the edge portion of a to a warm region of about 200 ° C. According to this, the extensibility of the outer panel a is improved, and even when the edge is hemmed with a large curvature as described above at an acute angle, the outer surface does not suffer from rough skin or minute cracks. The heating means 8 provided on the work receiver 2 is disposed immediately below the bent portion at the edge of the outer panel a so that the bent portion can be efficiently heated. In the pre-hemming step, the edge of the outer panel a is pressed inward over a predetermined bending line by the pre-heming edge 4 as shown in FIG. If the bent portion of the panel edge is not heated at this time, a thrust force F from the pre-hemming edge 4 is applied to the outer panel a to cause sharks as indicated by phantom lines, and the hemming process by the hemming edge 6 is performed. Although the shank remains as it is, in the present embodiment, since the resistance against bending of the panel edge is weakened by heating, the thrust force acting on the outer panel a is reduced, and no shark occurs. As is apparent from the above description, according to the present invention, even if the work is made of a material having a small elongation, such as an aluminum material, the surface of the outer surface becomes rough, minute cracks, and sharks are formed. The hemming process can be performed with a large curvature without occurrence of the following.

Hemming the pre hemming step by cross-sectional view [FIG 3] This invention hemming position according to an exemplary side view Figure 2 present invention of the hemming apparatus used in the practice of the BRIEF DESCRIPTION OF THE DRAWINGS [Figure 1] The present invention Sectional view of processing location [FIG. 4] Cross-sectional view of hemming processing location using conventional equipment [Description of symbols] a Outer panel (work) 2 Work receiver 4 Pre-hemming edge 6 Hemming edge 8 Heating means

Continuation of front page (56) References JP-A-4-351229 (JP, A) JP-A-50-46550 (JP, A) JP-A-3-216215 (JP, A) JP-A-4-52030 (JP, A) , A) Fully open 1987-193918 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B21D 39/02 B21D 19/08 B21D 37/16

Claims (1)

(57) [Claims] [Claim 1] A work receiver, a pre-hemming edge,
The hemming edge is heated by heating means to
Pre-hemming while heating the machining part to the warm area
Hemming process that performs hemming processing consisting of
A work device, wherein the work receiver is erected on a lower mold, and the pre-heming edge is erected on the lower mold so as to swing freely.
The hemming edge is vertically attached to the upper frame,
The upper edge is formed by inclining downwards outwardly, and the lower edge of the upper die is moved between the upper die and the swing frame.
Therefore, the first cam for swinging the swing frame to the machining position and the front cam
A second cam for retracting the swing frame from the processing position.
A driver cam is provided, and the work receiver, pre-heming edge and hemming edge
A hemming apparatus characterized in that heating means are provided in the vicinity of the processing part of the edge, respectively .