JPH0118812B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a method for deep drawing a metal foil into a tapered container with a flange and in which the diameter of the side wall of the container is gradually smaller than the diameter of the container. Specifically, the present invention relates to a method for easily removing a container after deep drawing from a female mold.

``Prior Art'' A deep-drawn container with a flange with a tapered side wall has not been put to practical use because it is difficult to deep-draw the container when it is made of metal foil, and there is no known technique for taking out the container. It has been put into practical use with tinplate of 0.2 mm or more, steel plates such as stain-free steel, or aluminum plates, and the methods for forming and taking them out are as follows. Molding is performed using a tapered female metal die and a male metal die, and the stroke length is adjusted so that a predetermined amount of flange remains at the stroke end. The molded container remains in the female mold, but the container is removed by applying force to the bottom of the container from the outside to the inside of the container using a knock outer or the like. When the plate is thick, such as a steel plate or an aluminum plate, the container can be taken out using this method as well without deforming the container bottom or side wall.

``Problems to be solved by the invention'' In addition, a patent application regarding the deep drawing method for metal foil was submitted.
As disclosed in No. 58-136851, in the case of deep-drawn containers made of metal foil, the strength of the bottom and side walls of the container is weak. It becomes deformed and difficult to remove without damaging the container shape.

"Means for Solving the Problem" In view of the above-mentioned circumstances, the present invention has been developed as a result of repeated studies on a method for easily taking out a metal foil flanged tapered container from a female mold without damaging its shape. The purpose can be achieved by arranging a plurality of strokes in succession and having a mechanism in which the relative positions thereof are displaced according to the stroke position. This will be explained below according to the drawings. 1, 2, and 3 are drawing process diagrams based on the basic concept of the present invention. FIG. 3 is an enlarged view of adjacent parts of the female die, and FIGS. 7, 8, 9, and 10 are process diagrams of conventional drawing processing. As for the male type, Fig. 1, Fig. 2, Fig. 3, Fig. 7, Fig. 8,
In both Figures 9 and 10, the patent application 1983-
Disclosed in No. 136851. Although a male die combining an elastic material 8 and a rigid body 7 suitable for deep drawing of metal foil is illustrated, the structure and material of the male die are not limited. Here, the issue of container retrieval will be explained based on the prior art. When deep drawing metal foil, in order to avoid wrinkles on the side wall of the container, it is preferable to use elastic material 8 for a part of the male die and press the side wall of the container against the inner wall of the female die. In this case, the outer diameter of the elastic material 8 of the male mold is larger than the inner diameter of the female mold. In this case, if the molded container comes out of the female mold 16 while being fixed to the male mold, the female mold 16 is no longer restrained, and the elastic material pushes the container to expand, making it impossible to maintain the predetermined shape of the container. Therefore, in order to obtain a predetermined shape of the container, it is necessary to restrain the container with the wrinkle presser 6 and the female mold 16, and to extract only the male mold from the female mold, as shown in FIG. With the intention of obtaining a predetermined container shape in this way, the molded container was placed in a female mold 1.
However, in the state shown in FIG. 10, the female mold 16 and the container 15 within the female mold are quite firmly attached. The reason for the generation of this sticking force (hereinafter referred to as sticking force) is thought to be as follows. The strain in the circumferential direction during the drawing process is compressive strain, and when the male mold is unloaded, that is, the male mold is pulled out of the container, the side wall of the container tends to recover by the elastic compressive strain. It is thought that this restoring force presses the container into a female shape. The adhesion force of the entire container to the female mold is considered to be proportional to the product of the contact area between the container side wall and the female mold and the pressing force per unit area. This fixing force increases proportionally as the depth of the container increases, and if it exceeds the strength of the container, a knock outer applies a removal force of 10, deforming the bottom and side walls of the container when the container is removed. The present invention is based on the idea that the contact area between the side wall of the container and the female mold is kept small before the knockout outer applies the ejection force 10 to the bottom of the container. As an example based on this basic concept, FIGS. 1, 2, and 3 show drawing process diagrams in the case where two female dies are arranged in succession. Figure 1 shows the state before drawing, where the female mold A1 (the female mold on the side close to the male mold) and the female mold B2 (the female mold on the side far from the male mold) are held by a retainer 3, and the female mold is held between the female molds. is equipped with a spring 4 that applies a forcing force to widen the gap between the female molds. If a force greater than this spring load is applied, the female mold A1 and the female mold B2 can be slid up and down within the retainer 3. Note that the spring load is smaller than the wrinkle pressing force.
Further, the female mold B2 is connected to the rod 5, and the vertical movement of the press is transmitted thereto. Figure 2 shows the middle of the drawing process, and since the wrinkle pressing force is greater than the forcing force between the female molds, the drawing process is performed with the exit plane 12 of the female mold A1 and the entrance plane 11 of the female mold B2 in contact with each other. . FIG. 3 shows a state where the drawing process has been completed. When the wrinkle presser 6 returns to the initial position before the drawing process and the female die is released from the wrinkle press force, the female die A1 and the female die B2 are , the spring load changes the state from the contact state to the separated state. Due to the separation between the female molds and the tapered container side wall, the female mold B2 and the container side wall are separated, and the adhesion force between the female mold and the container side wall is due to the container side wall in contact with the female mold A1. This makes it very easy to take out with a knockout outer (not shown). The effect of the present invention decreases as the axial thickness 17 of the female mold A1 increases relative to the container depth. On the other hand, if it is too thin, when female mold A1 and female mold B2 separate, female mold B2
Due to the adhesion between the flange and the container wall, the container flange becomes
It may be drawn into the female mold A1. Therefore, the axial thickness 17 of the female die A1 is determined depending on the type of drawing material and the depth of the container. Furthermore, the inlet diameter 13 of the female mold B2 needs to be the same or smaller than the outlet diameter 14 of the female mold A1. If it is large, the diameter of the container at the inlet of the female mold B2 will be larger than the outlet diameter 14 of the female mold, and the ease of removal will not be improved. When making the size smaller, it is preferable that the difference between the exit radius of the female mold A1 and the entrance radius of the female mold B2 be slightly larger than the entrance shoulder R18 of the female mold B2.If the difference is made too large, wrinkles may occur. Alternatively, a phenomenon in which the side wall breaks may occur, which is undesirable. In explaining the content of the present invention, in order to facilitate understanding, the case where two female molds are arranged is shown as an example, but even if a larger number of female molds are arranged, the present invention will still work. Needless to say, the desired effect is achieved. In that case, it is necessary to apply a forcing force to separate each female mold, and to maintain the relationship between the outlet diameter and the inlet diameter of adjacent female molds in the same manner as in the above two cases. In addition, although the female mold is held and guided by a retainer and the force is applied by a spring, an air cylinder may be used instead of the spring, and the method of applying the force,
The holding and guiding method is not limited.

"Example" Next, examples of the present invention will be described.

Two female molds were arranged as shown in FIG. The combinations of female mold A1 on the side close to the male mold and female mold B2 on the far side were shown in Table 1. The diameter of the female type A1 is 65 mm, and the taper angle is
The angle was set to 4° for both female type A1 and female type B2. The male type is rigid body 7
The diameter of the tip of the elastic material 8 was 54 mm, and the diameter of the tip of the elastic material 8 was 66 mm. Other dimensions are as shown in Table 1. As the molding material 9, 75 μm steel foil,
Drawing molding was performed with palm oil lubrication using 100 μm aluminum foil, 100 μm copper foil, and 20 μm polyester film laminated on both sides. The evaluation was performed by molding a container with a depth of 45 mm using the above tool and checking whether or not the container was deformed when taken out from the female mold.

"Effects of the Invention" As is clear from the results in Table 1, according to the method of the present invention, there is no deformation of the container at the time of taking out, indicating that the present invention is excellent in taking out the container. In the embodiments, the cross-sectional shape of the container is circular, but it goes without saying that even if the cross-sectional shape is square or any other shape, it is effective as long as the side wall is tapered.

[Brief explanation of drawings]

1, 2, and 3 are drawing process schematic diagrams showing the basic concept of the present invention. FIG. 1 shows the state before drawing, FIG. 2 shows the state in the middle of drawing, and FIG. The figure shows the state at the end of the drawing process. 4, 5, and 6 are enlarged views of adjacent portions of the female molds in FIGS. 1, 2, and 3, respectively. FIG. 7, FIG. 8, FIG. 9, and FIG. 10 are schematic diagrams of the drawing process of the prior art. FIG. 7 shows the state before drawing. 8 and 9 show the state in the middle of the drawing process, and FIG. 8 shows the state when the male die advances and the forming progresses. FIG. 9 shows the state when molding is completed and the male mold is retracted. FIG. 10 shows the state at the end of the drawing process. 1... Female mold A, 2... Female mold B, 3... Retainer, 4... Spring, 5... Rod, 6... Wrinkle presser, 7... Rigid body, 8... Elastic material, 9... Cover Molding material, 10... Removal force, 11... Inlet plane,
12... Outlet plane, 13... Inlet diameter, 14... Outlet diameter, 15... Container, 16... Female mold, 17... Axial thickness of female mold A1, 18... Inlet shoulder R, 19...
... Cavity.

【table】

[Table] Good Bad

Claims (1)

[Claims] 1. A plurality of female molds in which the cavity inner diameter gradually decreases compared to the inlet diameter are arranged consecutively in the molding direction, and the female mold inlet diameter on the side far from the male mold of the adjacent female mold is set between the entrance and the adjacent female mold. During the molding process, adjacent female molds touch at the exit plane and entrance plane, and after molding is completed and the male mold retreats from the inside of each female mold cavity, each female mold A method for deep drawing metal foil, which is characterized by forcibly separating the exit plane and the entrance plane of a mold, and has excellent ease of taking out a molded container.