JPH11169978A - Manufacture of deep drawn container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the formation of a fine radius in a bottom surface part of a deep drawn container by executing the deep drawing with a radiused part formed at the connected part between the projecting part and the side wall part of a punch and a radiused part formed at the opening end side and the inner diameter side wall part of a die and executing the formation with the recessing part of the punch and the projecting part of the die. SOLUTION: The projecting part 5a of a female die 5 is formed as ramming state with the recessing part 4a of the punch 4 through a material 1b, and the recessing part 2a of the container is formed and further, in the connecting part 2d between the recessing part 2a and the side wall part 1a of the container, the fine radius R formed on the connecting part 4d of the punch 4 is transfer-formed. Since a gap 9 between the recessing part 5b of the female die 5 and the projecting part 2b of the container exists, the ramming is executed only in the position at the projection part 5b of the female die 5 and the working load is reduced. At the time of deciding the dimension in the height relation between the recessing part 5b of the female die 5 and the projecting part 4b of the punch 4, the gap 9 can arbitrarily be set by considering the thickness of the material 1b. Therefore, the fine radius R at the bottom surface of the deep drawn container can be formed with the deep drawing work.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a drawn container, and more particularly, to a method for forming a small radius portion (less than the thickness of a material) on a bottom surface.

[0002]

2. Description of the Related Art In the case of forming a fine R in a bottom portion of a drawn product, as in Japanese Patent Application No. 167303/1985, the R dimension is gradually reduced in several drawing steps. There is a way.

[0003] Further, after drawing, a forming step is added or cutting is performed.

[0004]

When drawing is performed with a punch and a die, the shape of the R portion at the tip of the punch is transferred to the bottom of the drawn container. When it is desired to form a small R portion (less than the plate thickness) on the bottom portion, it is necessary to make the R portion of the punch a very small R. Cracks or necking can occur, leading to breakage of the material.

In order to prevent this phenomenon, in drawing of a cylindrical container, the R dimension at the tip of the punch is usually set to be at least four times the plate thickness.

For this reason, there are a method of sequentially reducing the R dimension in several drawing steps, a method of forming only the bottom portion in a separate step after drawing, and the like.
Further, there is a problem that the peripheral portion is deformed due to the molding of the bottom portion and the dimensional accuracy is deteriorated. Eventually, since the number of processing steps increases, it is necessary to increase the number of dies and the number of press devices, which increases the cost. In addition, there is a method in which the R portion is made minute by cutting, but the productivity is deteriorated and the cost is increased.

SUMMARY OF THE INVENTION An object of the present invention is to provide a manufacturing method with high productivity and high processing accuracy in a processing method for forming minute R on the bottom portion of a drawing container.

[0008]

In order to achieve the above-mentioned object, uneven portions corresponding to the top surface of the punch and the bottom surface of the die are provided, and R and R are formed at the connecting portions between the projecting portions of the punch and the side walls.
The drawing method is performed in such a manner that drawing is performed on the portion and the R portion formed on the open end side of the die and on the inner diameter side wall, and after forming is performed on the concave portion of the punch and the convex portion of the die, the drawing process is completed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 1, 2, 3, 4, 5, 5, 6, 7, 8, and 9. FIG. FIG. 1 shows an external view of a container according to the present invention. Container 1
Is manufactured by drawing, and has a bottom surface 2 and an opening 3. A concave portion 2a, a convex portion 2b, a convex portion 2b and a side wall portion 1 of the container 1 formed simultaneously with the drawing process are formed on the bottom surface portion 2.
a, and a connection 2d between the recess 2a and the side wall 1a of the container 1 are continuously formed. FIG. 2 is a longitudinal sectional view of the container 1 shown in FIG.

FIG. 3 is a sectional view showing a mold structure according to the present invention. A concave portion 4a and a convex portion 4b are formed on the upper surface of the punch 4 so as to face the concave portion 2a and the convex portion 2b formed on the bottom portion 2 of the container 1, and a connecting portion 4c between the side wall portion 4e of the punch 4 and the convex portion 4b. An R shape required for drawing is formed, and a connection portion 4d between the side wall portion 4e and the concave portion 4a is formed in a minute R shape continuously, and is attached to the press bolster 10.

[0011] The convex part 5 a and the concave part 5 b facing the concave part 4 a and the convex part 4 b formed on the upper surface of the punch 4 are formed in the megata 5, and are fitted to the inner diameter side wall part 6 b of the die 6.
The die 6 is mounted on the press slide 9 together with the megata 5. The wrinkle fly 7 is fitted along the side wall 4 e of the punch 4 and is placed on the cushion pin 8. The cushion pin 8 serves to transmit the pressure of the die cushion cylinder built in the press device to the wrinkle stick 7.

One example of a process for processing the drawn container of the present invention will be described with reference to FIGS. 4, 5, 6, and 7. FIG. FIG. 4 is a cross-sectional view illustrating a state where the material 1b of the container 1 is set in a mold. The material 1b is set on the wrinkle fly 7 with its center positioned. After the material 1b is set, as the press slide 9 descends, the megata 5 and the die 6
It moves down in the direction b, and the end face 6c of the die 6 comes into contact with the material 1b.

FIG. 5 is a sectional view showing a processing state immediately after the drawing processing is started. The material 1b is connected to a connecting portion 4c formed on the punch 4 and a connecting portion 6a between the end surface 6c formed on the die 6 and the inner diameter side wall portion 6b under the condition that the die cushion pressure is applied by the end face portion 6c of the wrinkle fly 7 and the die 6. Drawing is performed by the inner diameter side wall 6b. At this time, a space 4e exists due to a step between the convex portion 4b and the concave portion 4a of the punch 4, and the material 1b is not drawn by the minute R portion 4d formed in the punch 4 due to the space 4e. Drawing is performed only at the connection portion 4c. Furthermore, the megata 5 is in a position not yet in contact with the material 1b.

FIG. 6 is a cross-sectional view showing a state in which the megata 5 has come into contact with the material 1b and the formation of the concave portion 2a has been started. The upper surface 2b of the material 1b is deformed by the convex portion 5a of the megata 5, and the concave portion 2a is being formed. The connection portion 2c has already been processed by drawing.

FIG. 7 is a sectional view showing a state at the time when the drawing according to the present invention is completed. The convex portion 5a of the megata 5 is in a state of sticking to the concave portion 4a of the punch 4 via the material 1b, the concave portion 2a of the container 1 is formed, and the concave portion 2a of the container 1 and the side wall portion 1 are formed.
The minute R formed on the connecting portion 4d of the punch 4 is transfer-molded to the connecting portion 2d with a.

Since the gap 9 is provided between the concave portion 5b of the megata 5 and the convex portion 2b of the container 1, the body is attached only to the convex portion 5a of the megata 5, and the processing load can be reduced.
The gap 9 can be arbitrarily set by considering the thickness of the material 1b when determining the size of the height relationship between the concave portion 5b of the megata 5 and the convex portion 4b of the punch 4. In the present embodiment, the dimension and shape of the connecting portion 4c formed on the punch 4 are important points for enabling drawing. 8 and 9, in this embodiment, when a cold-rolled steel plate having a plate thickness t = 1.6 to 2.0 mm is used, the connecting portion 2d of the container 1 is set to R0.1 m.
The results of an experiment performed to reduce the value to m or less are shown. In this experiment, the convex portions 2b and the concave portions 2a were arranged at four symmetrical positions.

The inner diameter of the container is φD (φD = the outer diameter of the punch 4), the step between the concave portion 4a and the convex portion 4b of the punch 4 is H, and the arc length of the connecting portion 4c of the convex portion 4b of the punch 4 is W, when the arc length of the connecting portion 4d of the concave portion 4a of the punch 4 is X, the circumferential length L of φD in the range of φD = 60 to 80 (=
D * π), it was confirmed that processing was possible if the relationship of X / L ≦ 20% was satisfied.

FIG. 9 shows an appropriate range of the H dimension in this case. Processing is possible with X / L ≦ 20%, but W = 20%
Can be processed in the range of H = 3.5 to 8 mm. W =
At 10%, it is possible to work in the range of H = 1.5 to 5.5 mm, and when X / L becomes small, H needs to be small.

This is because a tensile stress is locally generated in the concave portion in this processing, so that when W / L is large (X is reduced) and H is large, the material elongation λ (≒ 2 * H / X) becomes large, and cracks, necking and the like occur. However, this result is applied to a cold-rolled steel sheet, and the dimension setting is not limited to this, since the material characteristics of other metal materials may significantly change.

In this embodiment, the convex portions 2b,
Although the projections 4b of the punch 4 are arranged at symmetrical positions, they can be processed even if they are asymmetric. Further, the present invention can be applied to a polygonal container. Further, processing can be performed even when a convex portion is provided only in the outer peripheral portion of the container 1 and a concave portion is provided in the central portion.

[0021]

According to the present invention, it is possible to form a small R on the bottom portion of the drawn container in the drawing process, thereby eliminating the post-process, improving the productivity and obtaining a product with high dimensional accuracy. it can.

[Brief description of the drawings]

FIG. 1 is an external view of a squeeze container according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view taken along line AOA of FIG.

FIG. 3 is a longitudinal sectional view of a mold structure according to the present invention.

FIG. 4 is a longitudinal sectional view showing a state in which a material is set in a mold of the present invention.

FIG. 5 is a longitudinal sectional view of a state in which processing has been started using the mold of the present invention.

FIG. 6 is a longitudinal sectional view of a state in the middle of processing using the mold of the present invention.

FIG. 7 is a longitudinal sectional view showing a state in which processing has been completed using the mold of the present invention.

FIG. 8 is an external view of a squeeze container of the present invention.

FIG. 9 is a graph showing a processing range of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Restriction container, 2a ... Convex part formed in the restriction container, 2b
... Recesses formed in the squeeze container, 2c ... connection portions formed in the squeeze container, 4 ... punches, 5 ... megata, 6 ... dies.

Claims (4)

[Claims] 1. A method of drawing a metal plate into a cup between a punch and a die, wherein an uneven portion is provided on an upper surface of the punch, a ridge is arranged on a bottom surface facing the open end side of the die, and a metal plate is provided on the upper surface of the punch. The convex portion on the upper surface of the punch is provided with a convex and concave portion corresponding to the formed concave and convex portion, and an R portion which is in contact with the metal plate at the time of drawing at a connection portion with the punch side wall portion is formed on the convex portion on the upper surface of the punch. An R portion formed on the punch convex portion and the punch connecting portion, an R portion formed on the die open end side, and an inner diameter side wall portion are drawn, and formed between the convex portion of the META and the concave portion of the punch, A method for producing a drawn container, wherein drawing is completed. 2. A method of drawing a metal plate into a cup between a punch and a die, wherein at least one concave / convex portion is provided on an upper surface of the punch, and a metal plate is disposed on a bottom surface facing the open end of the die. An uneven portion corresponding to the uneven portion provided on the upper surface is provided on the megata, and a convex portion on the upper surface of the punch is formed with an R portion which is in contact with the metal plate at the time of drawing at a connection portion with a punch side wall portion, The metal plate has a concave portion provided on the upper surface of the punch and an R portion formed on the punch convex portion and the punch connecting portion in a state where a space is secured, an R portion formed on the die open end side, and an inner diameter side wall portion. A method for producing a drawn container, wherein the drawn container is drawn and formed between the convex portion of the megata and the concave portion of the punch, and drawing is completed. 3. A method for drawing a metal plate into a cup between a punch and a die, wherein at least one concave and convex portion is provided on the upper surface of the punch, and a metal plate is arranged on a bottom surface facing the open end side of the die. An uneven portion corresponding to the uneven portion provided on the upper surface of the punch is provided on the mortar, and the convex portion on the upper surface of the punch has a sufficient contact with the metal plate at the time of drawing at a connection portion with the side wall of the punch. An R portion is formed, and a connection portion with the punch side wall portion is formed in the punch recess with an R portion having a thickness equal to or less than the thickness of the metal plate, and the metal plate secures a space with a recess provided on the upper surface of the punch. In this state, drawing is performed by the punch convex portion and the R portion formed on the punch connecting portion, the R portion formed on the die open end side, and the inner diameter side wall portion, and is formed between the convex portion of the megata and the concave portion of the punch. By being said gold Method of manufacturing a draw-formed container, characterized in that the thickness following R portion of the plate is formed. 4. The method according to claim 1, wherein the metal plate is a cold-rolled steel plate, and at least one connecting portion between the concave portion and the side wall portion of the punch is a side wall of the punch. A method for producing a drawn container, characterized in that each of the drawn portions has an arc length of 20% or less with respect to the peripheral length of the portion.