WO1998051426A1

WO1998051426A1 - Method for blanking blanks for cupping, blank, and cylindrical can formed from that blank

Info

Publication number: WO1998051426A1
Application number: PCT/JP1998/002052
Authority: WO
Inventors: Yasuyuki Ikeda; Keiichi Shimizu
Original assignee: Toyo Kohan Co., Ltd.
Priority date: 1997-05-09
Filing date: 1998-05-08
Publication date: 1998-11-19
Also published as: AU7234998A

Abstract

A method for blanking blanks for use in cupping in a high yield so as to form cylindrical cans of a low earing ratio (variations in cylinder can height) with those blanks; blanks blanked by that method; and cylindrical cans of a low earing ratio formed with those blanks. The method for blanking is characterized in that blanks of a basically hexagonal shape, with each pair of the opposite sides of the hexagon parallel to each other and each corner of the hexagon formed in an arc shape, are blanked out of a long rolled metallic plate.

Description

Description Blanking method for blanks for cylindrical drawing, blanks and cylindrical cans formed from the blanks

The present invention relates to a method of blanking a blank for cylindrical drawing from a metal plate, a blank punched by using the blanking method, and a cylindrical can formed by using the blank. In more detail, the blank used for cylindrical drawing

10 Blanking method to obtain a cylinder with good yield and low ear ratio (variation in the height of the cylindrical can) of the cylindrical can formed from the blank, blanks blanked by that method, and from blanks It relates to a molded cylindrical can. Background art

f Conventionally, when a metal plate is drawn into a cylinder, a blank punched into a disk is used. However, when blanks such as discs are punched from a long metal rolled plate, the blanks to be punched are arranged in a staggered manner, and the blanks between adjacent blanks are arranged so as to minimize unnecessary parts. However, an unnecessary portion of a substantially triangular shape is inevitably generated as a scrap portion. This scrap, and the ears

7. In order to reduce the occurrence of parts, punching the blank into a non-circular shape is a

It is disclosed in Japanese Patent Publication No. 112570/1999. In Japanese Patent Publication No. 7-111125, the most efficient method is to punch a blank in a dodecagonal shape, assuming that the material has ears in the direction parallel or perpendicular to the rolling direction during drawing. It is a target.

^ Also, an arc is formed at the corner of the dodecagon, and its curvature is 2

It discloses that the ear ratio is minimized when it is 5 to 40%. The inventors of the present invention conducted various experiments to change the anisotropy, the number of blanks punched in the sheet width direction, and the like in order to reduce the occurrence of unnecessary portions in blanking. Based on the above, it has been found that it is most preferable to perform blanking in a shape in which a corner is rounded with a certain radius of curvature.

ζ The present invention provides a blanking method that reduces unnecessary portions other than blank portions to be punched out when a metal plate is drawn into a cylinder and reduces the occurrence of ears when the blank is formed into a cylinder. And a blank blanked by the method, and a cylindrical can formed using the blank. Disclosure of the invention

The present invention provides a hexagonal blank formed by forming two hexagons whose opposite sides are substantially parallel to each other in an arc shape from a long rolled metal plate. A pair of substantially parallel two sides facing each other is punched out at an angle of 80 to 100 ° with respect to the rolling direction of the metal plate. Blanking method,

The radius of curvature (R) of the circular arc and the diagonal length of the shape in which each corner around the hexagon is formed in the shape of an arc (distance between opposing corners after rounded corners, and so on: 2 r ) Ratio (R

Z 2 r) is 0.15 to 0.45,

0 Further, the hexagon is a regular hexagon,

Furthermore, at least three blanks are punched out in a zigzag manner in the width direction from the long rolled metal plate,

Furthermore, when punching at least three or more blanks in the width direction, the blanks are continuously punched in parallel in the longitudinal direction.

Furthermore, at least one surface of the metal plate is coated with a thermoplastic resin. The present invention is also directed to a blank formed by punching using any of the blanking methods for cylindrical drawing blanking described above.

Further, the present invention is also directed to a cylindrical can formed by using the above blank. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 (a) is a schematic diagram when punching a circular blank, and FIG. 1 (b) is a schematic diagram when punching such that an angle formed by one side of a hexagon with respect to the rolling direction of the steel plate is 90 °. Figure 2 (c) shows whether the angle formed by one side of the hexagon with respect to the rolling direction of the steel sheet is 90 °.

10 is a schematic diagram in the case of punching out at a shifted angle. (D) in Fig. 3 is a schematic diagram when punching is performed so that the angle formed by one side of the non-parallel hexagon is 90 °, and (e) is the same length of each side. FIG. 9 is a schematic diagram in a case where punching is performed so that an angle formed by one side of a hexagon having equal angles and different angles of adjacent angles is 90 °. (F) in Fig. 4 shows that the six angles are equal and the rolling direction

(This is a schematic diagram in the case where punching is performed so that an angle formed by one side of a hexagon having a length of two sides perpendicular to 5 different from the lengths of the other four sides is 90 °.

The description of the reference numerals in these figures is as follows.

2 r diameter or diagonal length

角度 The angle between one side of the hexagon and the rolling direction of the steel sheet

ΖΌ a Angle of one corner of a hexagon where adjacent angles are different from each other

β The angle of one other corner of the hexagon whose adjacent angles are different from each other a The length of two sides perpendicular to the rolling direction of the hexagon whose six angles are equal b The angle of each of the six angles Of the four sides except the two sides perpendicular to the rolling direction of the hexagon

5 BEST MODE FOR CARRYING OUT THE INVENTION The present invention reduces unnecessary portions other than blank portions to be punched when a metal plate is drawn into a cylinder and reduces the occurrence of ears when the blank is formed into a cylinder. A wide variety of studies were conducted with the aim of providing a blanking method to reduce the extent of the ears generated in the blank and a blank and a cylindrical can molded using the blank.5 A blank having a substantially parallel hexagonal basic shape and rounded corners around the hexagon is used as a pair of two substantially parallel sides of the hexagon facing each other. The blank is punched at an angle of 85 to 95 ° with respect to the rolling direction of the metal plate, and at an angle of 80 to 100 ° depending on the anisotropy of the metal material. Be cut off Reducing the unnecessary portion other than the rank portion, and a low level occurrence ear upon forming form the blank into a cylindrical, it found that efficiently can be a blank cutout.

Hereinafter, the present invention will be described in detail. First, a circle (diameter: 2 r = l 50 mm), a regular dodecagon and a regular hexagon (each diagonal length: 2 r == 150 mm) are used as the basic shape 5, and each corner is defined as An experiment was conducted on the yield (unnecessary part generation rate) when three types of blanks of a circular shape (radius of curvature: R = 0 to 50 mm) were punched from a long cold-rolled steel sheet. A long rolled steel sheet with a constant thickness of 0.18 mm, with the same spacing between adjacent blanks and the same margin at both ends in the sheet width direction, in the blank shape of each figure above, in the sheet width direction The same number (n = 2, 3, 5, 7) o was punched out in a staggered manner so as to be continuously aligned in the longitudinal direction. For the regular hexagonal and regular dodecagonal blanks, a pair of two opposite parallel sides was set to be perpendicular to the rolling direction. Table 1 shows the results.

As shown in Table 1, when the blanks are circular, the yield increases as the width of the blank is increased and the number n of blanks punched in a staggered manner in the width direction increases. If the blank is a dodecagon S, the yield will be higher than in the case of a circle. However, the number of blanks punched in a zigzag shape in the sheet width direction and the radius of curvature R that rounds the corners into an arc are Therefore, although slightly different, only a yield improvement of about 2% can be achieved. On the other hand, if the blanks are hexagonal, either circular or dodecagonal, regardless of the number of blanks n punched in a zigzag pattern in the width direction of the plate and the radius of curvature R for rounding the corners in an arc shape, Higher yield than in the case of the blank. In the case of punching with five blanks having this hexagon as the basic shape, the yield varies depending on the radius of curvature R that rounds the corners in an arc shape, and the yield decreases as the radius of curvature R increases. That is, there is an upper limit of the radius of curvature R for achieving the target yield. On the other hand, the yield can be improved by reducing the radius of curvature R, but even if the anisotropy of the metal material or the drawing method is changed, it is possible to obtain a drawn can with a low ear ratio in the intended drawing. I can't. That is, there is a lower limit of the radius of curvature R in terms of ear ratio. As shown in Table 1, when the number n of blanks punched in the width direction of the plate is 2 or less, the yield is low for blanks of any of the circles, dodecagons, and hexagons. The number n of blanks to be punched out is preferably at least three or more.

Next, punching experiments were also performed on the number of blanks obtained from a certain amount of cold-rolled steel sheets. Punching blanks of three different shapes using a long cold-rolled steel plate, a circular blank, and a blank with rounded corners based on regular dodecagons and regular hexagons, the number of blanks n in the width direction is 7 Was carried out in the case of For circular blanks, seven sets of die sets for punching circular blanks were prepared, and three sets were placed in the front row so that they were on the same line in the direction perpendicular to the cold rolling direction (steel width direction). , The other 4 sets-0 are in the back row, the centers of the die sets in the front and back rows are arranged in a staggered manner in the direction (longitudinal direction) parallel to the rolling direction, and the intervals between the circular blanks are equally spaced It was arranged so that it could be punched out, and attached to a continuous punching press. The margin (side bridge) in the plate width direction was made equal at both ends. Continuous blank punching of 1 ton of cold-rolled steel sheet in this way yielded about 33,000 blanks.

5 For a blank with a regular dodecagonal shape and rounded corners, the radius of curvature after rounding the Z-angle is RZ 2 r = so that the blank area is the same as the circular blank. The corners were rounded at 0.07. Seven sets of die sets for punching blanks were prepared, with 3 mm as the front row and arranged so that they were on the same line in the direction perpendicular to the rolling direction during cold rolling of the steel sheet (the sheet width direction), and the other four sets as the back row. The centers of the front and rear die sets are arranged in a staggered manner in the direction parallel to the rolling direction (longitudinal direction), and the spacing between the pseudo dodecagonal brags is the same as that of a circular blank. They were arranged so as to be punched at intervals and attached to a continuous punching press. At this time, a pair of two parallel sides of the blank to be punched were perpendicular to the rolling direction. The cold-rolled steel sheet has the same steel type and thickness as that used for blanking blanks, and the margin (side bridge) in the width direction is the same as that used for blanking blanks. A sheet having a plate width adjusted to the above was used. When 1 ton of cold-rolled steel sheet was continuously punched out in this way, about 33900 blanks were obtained.

For blanks with regular hexagons and rounded corners, two blank shapes were punched. First, to set the blank area to be the same as the circular blank, diagonal length after rounding the radius of curvature Z at the corner: R no 2 r = 0.06 Seven sets were prepared, and three sets were arranged on the same line in the direction perpendicular to the cold rolling direction of the steel sheet (the sheet width direction) with the three sets as the front row, and the other four sets were set as the back row, and the die in the front and rear rows The center of the set is arranged in a zigzag pattern in the direction parallel to the rolling direction (longitudinal direction), and the pseudo-hexagonal blanks are continuously punched at the same interval as the circular blanks. It was attached to a punching press- ⁰ . At this time, a pair of two parallel sides of the blank to be punched were perpendicular to the rolling direction. The cold-rolled steel sheet is made of the same steel type and thickness as the one used for blanking blanks, and the margin (side bridge) in the width direction is the same as that for blank blanking. One having an adjusted plate width was used. Continuous punching of 1 ton of cold-rolled steel sheet in this way

^ A blank was obtained.

Next, when drawing the blank into a cylinder, the corners considered to be possible to form at a low ear rate We punched out a rounded corner with a regular hexagon with a large radius of curvature. That is, the radius of curvature after rounding the corners so that the blank area is the same as the circular blank: diagonal length after rounding: RZ 2 r = 7 sets of die sets for punching blanks with rounded corners at 0.32 3 sets are set as the front row, and they are arranged so that they are on the same line in 5 directions perpendicular to the rolling direction during cold rolling of the steel sheet (the sheet width direction), and the other 4 sets are set as the back row, The centers are arranged so as to be staggered in the direction parallel to the rolling direction (longitudinal direction), and continuous punching is performed so that the intervals between the pseudo-hexagonal blanks are the same as in the case of circular blanks and are evenly spaced. Attached to the press. At this time, the blank was blanked so that a pair of two opposite parallel sides was perpendicular to the rolling direction. The cold-rolled steel sheet has the same thickness and the same steel type as the one used for punching a circular blank, and the margin (side bridge) in the width direction is the same as that for punching a circular blank. The one having a plate width adjusted as described above was used. Continuous punching of 1 ton of cold-rolled steel sheet in this way yielded approximately 34,700 blanks.

\ 5 In this way, when blanks of the same thickness and the same area are punched from the same amount of steel sheet, the shape of the blank to be punched is basically a hexagon rather than a circle or a regular dodecagon and a rounded corner. It was confirmed that the rounded corner shape could significantly improve the blank removal yield.

In this way, blanks are formed into hexagons with rounded corners with a certain radius of curvature, and the number of blanks in the width direction is selected so that yield is as good as 0. It turned out to be possible. Furthermore, considering the manufacturing of dies for punching blanks, dies having a hexagonal cross section can be manufactured much more easily than dodecagonal dies having a complex punching cross section.

^ Next, based on the results of the blank removal described above, it was confirmed that it was excellent in yield to perform blank removal with a regular hexagon as the basic shape and rounded corners. Then, two types of long steel sheets A and B shown in Table 2 were subjected to electrolytic chromic acid treatment, and resin-coated steel sheets coated on both sides with polyester resin were used as test materials, circular blanks, and as shown below. As shown in Figs. 1 and 2, a blank with a regular hexagonal base shape and rounded corners with various radii of curvature is blanked from a long resin-coated steel plate 5 and drawn. And molded into cylindrical cans.

(Example)

[1] Circle (See Fig. 1 (a))

Diameter (2r): 98 mm

[2] Regular hexagon (See Fig. 1 (b))

[0 Diagonal length (2r): 98mm (where, diagonal length: distance between opposite corners after rounding corners, and so on)

Deflection in rolling direction (0): 90 ° (where 0 = with respect to rolling direction of steel sheet)

Angle formed by one side of hexagon, the same applies hereinafter) Radius of curvature of arc (R): 15mm, 22mm, 25mm, 29mm, r5 34mm, 44mm

[3] Regular hexagon (See Fig. 2 (c))

Diagonal length (2r): 98mm

Rolling direction deviation (0): 75 °, 80 °, 85 °, 95 °, 100 °,

105 °

o Arc radius of curvature: 34mm

Tables 3 and 4 show the conditions for blanking of the 20 types selected from the above conditions and the ear ratio of the obtained cylindrical cans. Ear ratio is defined by the following equation. That is, the height to the bottom of the can was measured at the valleys and peaks formed at the upper end of the cylindrical can, and the average value was taken as the average height (H), and the height at the highest peak and the lowest valley were measured. Height difference (m H)

If you hear ^

Ear ratio = (ΔΗ / Η) X 100 () Defined by ⁹

As shown in Table 3 and Fig. 1 (b), a regular hexagon was used as the basic shape, and the above-mentioned rolling direction declination was 90 °. The radius of curvature (RZ2r) is equal to or larger than a circular blank when the diagonal length (RZ2r) is 0.25 or more, or 5 indicates that it is possible to draw cylindrical cans with anisotropy below the ear ratio of the circular blank. found.

Also, as shown in Table 4 and Figure 2 (c), the parallel sides of the regular hexagon are set so that the declination in the rolling direction is slightly deviated from 90 °, and the corners are rounded into an arc to form a blank. If the deviation from the vertical direction is within ± 10 °, the yield does not decrease and the ear rate does not increase so much.If it is within ± 5 °, the yield is almost good and the low ear rate is low. It turned out to be obtained.

Furthermore, as shown in Fig. 3 (d), when a pair of sides of the hexagon are non-parallel to each other and the corners are rounded into an arc shape and blanked, the degree of deviation from parallel is small. However, as long as they are substantially parallel, the ear ratio is not so high, and a good ear ratio can be obtained.

Furthermore, as shown in Fig. 3 (e), the sides of the hexagon are equal in length, the angles of a pair of opposite corners are equal, and the angles of adjacent corners are different, so that the corners are circular. When the blanks are rounded in an arc shape, the ear ratio does not increase so much as long as there is little deviation from the adjacent angle of 120 °, and almost good ear ratio can be obtained. W Furthermore, as shown in Fig. 4 (f), the angles of the six corners are equal, and the length of the two sides perpendicular to the rolling direction of the six sides is different from the length of the other four sides. When the corners are rounded into an arc and blanked, the ear ratio does not increase so much as long as the ratio of the different lengths is low, and almost good ear ratio can be obtained.

Next, a blank (diameter: 160 mm) and rounded corners of a regular hexagon 25 (diagonal length: 160 mm, R / 2r: 0.34) were blanked out from sample material A in Table 1. First, a drawn can with a can diameter of 100 mm was used. Next, by redrawing, a redrawn can with a can diameter of 80 mm did. This redrawn can was ironed at the same time as the redrawing to obtain a cylindrical drawn ironed can with a diameter of 66 mm. Of the obtained drawn and ironed cans, the ear ratio of cans molded from circular blanks was 12.5%, and the ear ratio of cans molded from RZ2r blanks with rounded corners of regular hexagons was 14 0%, which was almost the same as that of cans molded from circular blanks. Industrial applicability

In the present invention, a blank is punched out in a shape in which a hexagon whose two sides facing each other are parallel is a basic shape, and each corner around the hexagon is rounded in an arc shape, and the blank is subjected to a cylindrical drawing process. Unnecessary portions other than the blank portion to be formed are reduced, and the occurrence of ears when the blank is formed into a cylinder is reduced, so that material can be efficiently removed.

Yield when blank is circle

R hi (piece)

(mm) 2 3 5 7

0 82.8 85.1 87.0 87.8 Yield when blank is dodecagonal

R hi (piece)

(mm) 2 3 5 7

0 84.8 87.1 89.0 89.8

5 84.8 87.1 89.0 89.8

10 84.8 87.0 89.0 89.8

20 84.6 86.9 88.8 89.7

30 84.5 86.7 88.7 89.5

40 84.2 86.5 88.4 89.2

50 83.9 86.2 88.1 88.9 Yield when blank is hexagonal

R n (pieces)

(mm) 2 3 5 7

5 84.7 89.0 92.8 94.5

10 84.8 89.2 92.8 94.5

20 85.6 89.4 92.8 94.3

25 85.7 89.4 92.6 94.0

30 85.7 89.3 92.3 93.7

35 85.6 89.1 92.0 93.3

40 85.5 88.8 91.6 92.8

45 85.3 88.4 91.1 92.3

50 85.1 88.0 90.6 91.7 Table 2

Breakdown of test material

(Note) DR (%) * 2.8mm thick hot-rolled sheet is first cold-rolled, annealed at 680 ° C for 1 minute, and secondarily cold-rolled at a rolling ratio of% to achieve a thickness of 0.18. did.

Full Hard * Thickness 2.8 Hot rolled sheet of ram is cold rolled to a thickness of 0.18 nm.

PET 'polyethylene terephthalate

ポリエチレン Polyethylene isophthalate

Blanking conditions and ear ratio (1) Sample material Plank shape Ear ratio No. No. Basic shape Rolling direction R / 2 r (%) Deflection (0)

1 A yen 5.5

(Fig. 1 (a)) 0.5

2 B 14.5

3 A 0.15 20.5

4 A 0.22 15.5

5 A 0.25 11.0

6 A 0.30 9.5

7 A 0.34 '7.5

8 A 0.44 6.5 Regular hexagon 90 '

9 B (Fig. 1 (b)) 0.15 18.0

10 B 0.22 14.5

11 B 0.25 10.5

12 B 0.30 9.0

13 B 0.34 9.0

14 B 0.44 7.5

Blanking conditions and ear ratio (2) Sample material Blank shape Ear ratio No. ¾ ■ &

W basic shape Rolling direction R / 2 r (%) Declination (0)

15 A 75 ° 20-5

16 A 80. 13.0

17 A 85. 8.5 Regular hexagon 0.34

18 A (Fig. 2 (c)) 95 ° 8.0

19 A 100. 12.5

20 A 105 ° 20.0

Claims

The scope of the claims -

1. From a long rolled metal plate, two sides facing each other are substantially parallel

'-A blank having a shape in which each corner of the C-shape is formed in an arc shape, and a pair of two sides of the hexagon opposite to each other is 80 to 100 ° with respect to a rolling direction of the metal plate. A blanking method for blanks for cylindrical drawing, characterized by punching out at an angle.

2. The ratio (RZ 2 r) between the radius of curvature (R) of the arc and the diagonal length (2 r) of the shape in which each corner of the hexagon is formed in an arc is 0.15 to 0. 4. The blanking method according to claim 1, wherein the blanking method is 4.5.

3. The blanking method according to claim 1, wherein the hexagon is a regular hexagon.

4. The blanking method according to claim 1, wherein at least three or more blanks are punched from the metal plate in a staggered manner in the width direction of the metal plate.

5. The blanking method according to claim 4, wherein the blank is punched continuously in a longitudinal direction of the metal plate in parallel.

6. The blanking method according to any one of claims 1 to 5, wherein at least one surface of the metal plate is coated with a thermoplastic resin.

7. A blank formed by using the blanking method according to any one of claims 1 to 6.

8. A cylindrical can formed by using the blank according to claim 7.