JP2562756B2 - Cylinder deep drawing die and cylindrical deep drawing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical deep drawing die for forming a metal plate having in-plane plastic anisotropy into a cup having a small earring, and a cylindrical deep drawing method.

[0002]

2. Description of the Related Art Double squeezing cans (DRD cans: Draw &
Red cans, DI cans (Drawn & Ir)
oned cans) are widely used as containers for fish meat, beverages, etc., respectively. Although these DRD cans and DI cans are manufactured through a drawing process, the drawn metal plate is not necessarily isotropic, so the can edge height is not uniform on the circumference of the can, and the can height is not uniform. A high portion (hereinafter referred to as a mountain portion) and a portion having a low can height (hereinafter referred to as a valley portion) are formed. If the degree of the peaks and valleys is large, the trim margin is increased accordingly, and the use efficiency of the material is deteriorated. Further, in ironing (Ironing), if the peaks and valleys are large, it becomes difficult to remove the can from the punch after processing. The degree of the peaks and valleys of the squeeze can (hereinafter referred to as ear ratio).
Ear ratio = (mountain can height-valley can height) / valley can height x 10
If 0) becomes large, such a problem will occur, so it is important to reduce the ear rate. These mountains and valleys are
It is formed because the in-plane plastic anisotropy exists in the metal plate, that is, the plastic anisotropy (generally expressed as Rankford value = plate width strain / plate thickness strain) differs depending on the in-plane direction. It is something. Here, the crystal anisotropy is closely related to the plastic anisotropy, and the composition of steel, the manufacturing history, and the like influence.
Therefore, if the composition of the steel and the manufacturing process are constant, peaks and valleys having the same ear ratio are formed in a specific direction such as the rolling direction or the direction perpendicular to the rolling direction. Techniques for reducing the ear rate are Japanese Patent Laid-Open Nos. 58-151426 and 6-SHO6.
2 to 161919, these are aimed at reducing the in-plane plastic anisotropy of the steel sheet by optimizing the contained components in the steel and the manufacturing process, that is, optimizing the characteristics of the work material. It is intended, and as in the present application, no consideration is given to the die shoulder, and no consideration is given to the processed surface.

[0003]

The ear ratio is calculated according to Japanese Patent Laid-Open No. 58-58-58.
151426, JP-A-62-161919, and the like, some improvement is made, but when the components of the metal plate and the manufacturing process are restricted, there is a limit to the improvement, and the components and the manufacturing according to a wide variety of products. Proper process optimization makes the process extremely complicated. INDUSTRIAL APPLICABILITY The present invention provides a cylindrical deep-drawing die capable of forming a metal plate, which has a large in-plane anisotropy and therefore has a large earring in a normal cylindrical deep-drawing, into a drawing can with a small earing. , And a cylindrical deep drawing method.

[0004]

According to the present invention, according to a normal drawing process, a metal plate having a large in-plane plastic anisotropy to be a draw can having a large ear rate is formed into a draw can having a small ear rate. (EN) Provided are a squeezing die and a squeezing method using the die. The drawing process is usually performed by using a die 4, a punch 5, and a wrinkle retainer 6 as shown in FIG. 3, but the present invention is to solve the problem of the present application by making the shoulder radius 7 of the die 4 different in the circumferential direction. Is the solution.
That is, if the components of the metal plate and the manufacturing process are constant,
Since the peaks and valleys are formed in a specific direction with respect to the sheet passing direction, the ear radius of the squeeze can is determined by making the shoulder radius of the die appropriate for the peaks and valleys. Is to reduce. The contents of the present invention will be described below.

For the purpose of reducing the ear rate, many studies have been made on the factors in drawing which are considered to affect the height of the can. The drawing process is a process of applying a force to the punch 5 to deform the die shoulder metal plate 9 and the die surface metal plate 10 through the drawing metal plate 8.
Various factors affect the height of the can after drawing. Power to press the metal plate 10, metal plate 10 and die 4, wrinkle retainer 6
The frictional force with and the die shoulder radius 7 etc. are the factors. Regarding the relationship between these factors and the can height, the former two are larger and the die shoulder radius is smaller, the can height becomes higher. That is the result. Here, we examined the possibility of optimizing these factors in terms of reducing the ear rate, that is, increasing the valleys and lowering the peaks. As a result, the former two optimizations, namely, the optimization of the frictional force by optimizing the surface roughness of the wrinkle pressing surface and the die surface, or the wrinkle pressing,
Even if the reduction force distribution is optimized by partially grinding the die surface, the ear ratio cannot be improved sufficiently, and the die shoulder radius should be set to an appropriate dimension according to the circumferential position. Proved to be the most effective. Therefore, as a result of many studies on the radius dimension of the die shoulder and the length in the circumferential direction thereof, the die shoulder has a shoulder radius of 0.3 to
Uniform small radius within 1.0 mm, 0.5-3.0
It consists of a large radius part that is uniform in the range of mm and a joint part that has a shoulder radius between them, (large radius part die shoulder radius)
It was found that a squeeze can with a small ear ratio can be obtained by a die of / (small radius part die shoulder radius) = 1.3 to 6.0. It is provided here together with the deep drawing method.

The reasons for limiting the scope of the claims of the present invention will be described below. As the drawing process progresses, the metal plate 10 on the die surface is drawn toward the center while the plate thickness increases, but the degree of increase differs in the circumferential direction, and the thicker part becomes a can after Become Tanibe. Here, from the relationship between the die shoulder radius and the can height, if the die shoulder radius of the valley portion is reduced, the valley portion should be further reduced in thickness and the ear rate should be reduced. . Based on the above idea, many tests were repeated for the die shoulder radius and the appropriate range was determined. Regarding the portion of the die with a small shoulder radius (small radius portion 1) shown in FIG. 1, the shoulder radius is 0.3 mm.
If it becomes smaller, the can wall is likely to break during drawing, so the lower limit was made 0.3 mm. Further, from the viewpoint of the effect of reducing the thickness, the upper limit is 1.0 mm. On the other hand, the shoulder radius of the portion with a large die shoulder radius (large radius portion 2) is determined in consideration of the shoulder radius dimension of the small radius portion, the plate thickness of the metal plate to be processed, etc.
It is 3.0 mm. When the thickness is 0.5 mm or less, the dimension becomes almost the same as the small radius portion, the thickness reduction rate does not change, and the can wall breaks easily. On the other hand, the large radius shoulder radius is 3.0m
When it is m or more, the dimensional difference from the shoulder radius of the small radius portion is large, and wrinkles are likely to occur on the can wall of the squeezed can. Further, the ratio of the shoulder radius of the large radius portion and the shoulder radius of the small radius portion is set to 1.3 to 6.0,
When the ratio is 1.3 or less, the thickness reduction ratio does not largely change between the large radius portion and the small radius portion, and when the ratio is 6 or more, wrinkles are likely to occur on the can wall. For the above reasons, the upper and lower limits are set.

Here, these small radius portion 1, large radius portion 2,
The circumferential length of the connecting portion 3 is determined according to the in-plane plastic anisotropy state of the metal plate to be processed, the ease with which wrinkles occur on the side wall of the can, and the like. Generally, when drawing a metal plate,
The number of peaks and valleys is 4 to 6, respectively. For example, in the case of four metal plates, the die small radius portion 1, the large radius portion 2, and the connecting portion 3 are 4, 4, 8 respectively.
Dice provided individually may be used. In the cylindrical deep drawing method of the present invention, the small radius portion 1 of the die shoulder,
The circumferential lengths of the large radius portion 2 and the connecting portion 3 are not fixed, but from the viewpoint of keeping the appearance (look) of the can after drawing processing, in general, the small radius portion 1 And the large radius portion 2 are preferably approximately the same length, and the length of the connecting portion is approximately 1/4 to 1/2 of the length of the small radius portion (or the large radius portion). preferable. Also, the shoulder radius dimensions of the small radius portion 1 and the large radius portion 2 are uniform, but the shoulder radius dimensions within the small radius portion and the large radius portion are within ± 10% of the respective average shoulder radius dimensions. If so, the object of the present invention can be achieved. Incidentally, when the metal plate having the same position of the peaks and the valleys but having a different degree is drawn, even if the dice having different shoulder radius dimensions of the small radius portion and the large radius portion are not used, Since the ear rate can be adjusted by adjusting the wrinkle holding force, it is not necessary to prepare many dice in advance. By partially changing the surface roughness of the die of the present invention by grinding or the like, it is possible to form a cylindrical deep-drawn can having a lower earring rate.

[0008]

EXAMPLES Examples will be described below. By weight ratio, C: 0.038%, Mn: 0.28%, Si: 0.01
%, P: 0.018%, AL: 0.052%, with the balance being iron and unavoidable impurities, and smelting in a converter.
Slab is made by continuous casting, and thickness is 2.0 by hot rolling.
It was a hot rolled sheet of mm. Then 0.30 by cold rolling
mm and 0.35 mm, two types of thickness, 0.35 mm
Then, box annealing and skin pass were performed. After that, tin plating was performed on both the plate thicknesses of 0.30 mm and 0.35 mm to obtain tinplate. These two types of brass plates were drawn with a cylindrical deep drawing die having a die shoulder radius shown in Table 1 at a drawing ratio of 1.6 (punch diameter; 87 mm), and the effect of improving the ear ratio was evaluated. The small radius portion, the large radius portion, and the connecting portion of the dies in Table 1 are 4 locations, 4 locations, and 8 locations on the circumference of the die shoulder portion, respectively.
They were arranged point-symmetrically with respect to the center of the die, and the ranges of one location were 50 degrees, 26 degrees, and 7 degrees, respectively. In the drawing process, the small radius portion corresponds to the valley portion and the large radius portion corresponds to the mountain portion. As is clear from the results in Table 1, the cylindrical deep-drawing die of the present invention is suitable for obtaining a squeezing can having a small ear rate.

[0009]

[Table 1]

[0010]

[Effects of the Invention] By using the die of the present invention in which the shoulder of the die has a small radius portion, a large radius portion, and a connecting portion, the small radius portion is made to correspond to the valley portion of the squeezing can, and drawing is performed to obtain the ear ratio. It is possible to obtain a squeezing can excellent in that point.

[Brief description of drawings]

FIG. 1 is a schematic view of a cylindrical deep drawing die having a small radius portion, a large radius portion, and a connecting portion thereof.

FIG. 2 is a cross-sectional view taken along the line AOB of FIG.

FIG. 3 is a schematic view of cylindrical deep drawing.

[Explanation of symbols] 1 small radius part 2 large radius part 3 connecting part 4 die 5 punch 6 wrinkle presser 7 shoulder radius 8 narrowing part metal plate 9 die shoulder metal plate 10 metal plate on die surface

Claims (2)

(57) [Claims] 1. A die for processing, wherein the die shoulder comprises a small radius portion, a large radius portion and a connecting portion connecting them, and the shoulder radius of the small radius portion is 0.3 to 1.0 mm. The shoulder radius of the radius part is 0.5 to 3.0 mm, and the (large radius part shoulder radius) / (small radius part shoulder radius) = 1.3 to 6.0. 2. A diaphragm can is formed by arranging it so that the circumferential position of the metal plate to be processed, which becomes the valley of the diaphragm can when forming the can, and the small radius portion of the die shoulder correspond to each other. A cylindrical deep-drawing method in which a drawn can is formed by arranging the circumferential position of the metal plate to be the peak of the can and the large radius of the die shoulder so as to correspond to each other.