JP2707974B2 - How to shape seamless cans - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for shaping a seamless can with a neck-in portion used for a carbonated beverage can, a beer can, a coffee beverage can, a fruit beverage can, and the like, and particularly to a pre-neck formed by a roll foam method. The present invention relates to a method for shaping an in-portion and a pre-flange portion.

[0002]

2. Description of the Related Art A seamless can 4 'is provided with a curved portion 4'd connected to the upper end of a body portion 4'c and a trapezoidal shape connected to the curved portion 4'd by a roll form method as shown in FIG. A pre-necked-in portion 4'g having a shoulder 4'e and a neck 4'f connected to the shoulder 4'e, and a pre-flanged portion 4 '.
h has been proposed simultaneously (Japanese Patent Laid-Open No. Hei 5-
277572). That is, the portion between the support 41 and the work roll 42 at the open end of the seamless can 4 ′ is pressed almost radially inward by the spinning roll 40, and at the same time, the support 41 and the work roll 42 are moved in the direction of the arrow. By shifting at a predetermined timing, the pre-necked-in portion 4'g and the pre-flanged portion 4'h are formed.

Since the shoulder 4'e of the pre-necked-in portion 4'g is formed by stretching, it becomes trapezoidal, and the radius of curvature of the curved portion 4'd is relatively small. Therefore, when the wall thickness is small, there is a problem that the bent portion 4'd has poor dent resistance, and the axial load tends to concentrate near the bent portion 4'd, so that the axial load strength is relatively small. In addition, the neck 4'f is inferior in roundness and concentricity with the body 4'c due to the instability inherent in the roll foam method, and there is a problem that troubles are likely to occur during double winding. Was. Pre-flanged part 4'h
When the tip is processed in the radial direction, wrinkles occur because the pressing force of the spinning roll 40 and the support 41 is not applied. Therefore, it has to be in the shape of an inverted trapezoid, and faces diagonally upward and outward. As a result, when the cover is placed on the pre-flange portion 4'h during the double winding, the tip portion abuts on the inner surface between the seaming panel and the curl portion of the cover, and satisfactory double tightening is performed. There was a problem that can not be. Further, in this case as well, there was a problem that the width variation was relatively large due to the instability inherent in the roll foam method.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to a pre-necked portion of a seamless can formed by a roll foam method, wherein the roundness of the neck, the concentricity with the body, the dent resistance of the shoulder, and the like. An object of the present invention is to improve the axial load strength and to shape a preflange into a flange portion having a uniform width with a shape suitable for double winding.

[0005]

SUMMARY OF THE INVENTION A method for shaping a seamless can according to the present invention comprises a pre-necked portion including a curved portion connected to a body, a trapezoidal shoulder connected to the curved portion, and a neck connected to the shoulder. In a method of shaping a pre-neck-in part and a pre-flange part of a seamless can having an inverted trapezoidal pre-flange part connected to a neck part, a bottom part of the seamless can is fixed to a chuck, and a neck inner surface is concentric with the chuck. The inner diameter of the front end portion is slightly larger than the outer diameter of the body portion of the seamless can in a state where the outer peripheral surface of the cylindrical portion of the riflange die is closely contacted, and the trapezoidal front processed surface and the rear processed surface which are expanded forward. Is advanced by pressing the curved portion and the vicinity thereof mainly inward in the radial direction by the front processed surface and the rear processed surface, and the curved portion and the vicinity thereof are pressed. Plastic deformation along the front processing surface and the rear processing surface, then slightly retreating the reforming die, the plastically deformed curved part and its vicinity, the part close to the front processing surface and the rear processing surface Except for the elastic deformation of
In a state in which the vicinity of the curved portion, the curved portion, and the shoulder portion of the body portion are in an inverted bowl shape as a whole, the riflange die is advanced, and the curvature portion connected to the base of the cylindrical portion of the riflange die and extends substantially in the radial direction. The pre-flange portion is pressed by a re-flange surface which is formed by a flat portion and whose end is defined by a step extending forward to form a flange portion extending substantially in the radial direction.

[0006] It is preferable that the angle α between the front processed surface and the rear processed surface of the reform die is larger than the angle β between the body and the shoulder of the seamless can. In addition, the bottom of the seamless can has a chime portion and a grounding portion, and the chuck has an inner peripheral surface in which the chime portion can be inserted exactly, and in a state where the chime portion is inserted into the chuck, the grounding portion is formed. The chuck and the bottom pad are preferably mounted on the bottom pad, and when the pre-flange portion is pressed by the re-flange surface, the chuck and the bottom pad are preferably buffered by a spring.

[0007]

With the bottom of the seamless can fixed to the chuck and the inner surface of the neck is brought into close contact with the outer peripheral surface of the cylindrical portion of the riflange die concentric with the chuck, the riflange die is advanced, so that the roundness of the neck and the torso can be improved. Concentricity is improved. The inner diameter of the front end portion is slightly larger than the outer diameter of the body portion of the seamless can, and the reforming die having a trapezoidal front processed surface and a rear processed surface that expands toward the front is advanced, and a front processed surface and a rear portion are formed. The bent portion and its vicinity are mainly pressed inward in the radial direction by the processing surface, and the bent portion and its vicinity are plastically deformed along the front processed surface and the rear processed surface. By retracting the reform die, the plastically deformed curved part and its vicinity, except for the elastic deformation of the part close to the front processed surface and the rear processed surface, the curved part near the trunk,
The curved portion and the trapezoidal shoulder have an inverted bowl shape as a whole, and an inverted bowl-shaped shoulder 4e (FIG. 7) is formed. The shoulder portion 4e has an inverted bowl shape in which the axial load is evenly distributed, so that the shoulder portion 4e has a higher axial load strength than the pre-necked portion 4'g having the curved portion 4'd and the trapezoidal shoulder 4'e. ing.

The pre-flange is formed by advancing the re-flange die, the re-flange surface comprising a curvature connected to the base of the cylindrical portion of the re-flange die and a substantially radially extending flat portion, the end of which is defined by a step extending forward. To form a substantially radially extending flange. Therefore, the flange portion extends substantially in the radial direction like a normal flange portion, and is suitable for double winding.
Since the end of the riflange surface is defined by a step extending forward, a flange portion having a uniform width can be obtained. By using a reforming die in which the angle α formed by the front processed surface and the rear processed surface is larger than the angle β formed by the body and the shoulder of the seamless can (claim 2), the inverted bowl shape having a relatively large radius of curvature is obtained. A shoulder 4e can be formed. Since the shoulder portion 4e has a larger radius of curvature than the curved portion 4'd, the dent resistance is more excellent.

The bottom of the seamless can has a chime portion and a grounding portion, and the chuck has an inner peripheral surface into which the chime portion can be inserted exactly. The part is placed on the bottom pad, and when the pre-flange part is pressed by the re-flange surface, the chuck and the bottom pad are cushioned by a spring. The chime portion is easily buckled by an axial load when the pre-flange portion is pressed by the re-flange surface, but is difficult to buckle because it is in close contact with the inner surface of the chuck. The height of the seamless cans 4 'usually has slight variations. However, when the pre-flange portion is pressed by the re-flange surface, the bottom pad on which the chime portion and the ground portion are placed is buffered by the spring, so that the seamless can 4 'having a can height slightly higher than the reference can height is shaped. Even in this case, there is no possibility of buckling of the shoulder 4e (particularly the upper half thereof) or the trunk.

[0010]

1 is a transfer turret, 2 is a main turret, and 3 is a reject turret. The seamless can 4 'having the pre-necked-in portion 4'g and the pre-flanged portion 4'h (see FIG. 5) formed by a roll-form type neck-in / flange forming machine (not shown) is an intermediate turret (not shown). From the transfer that rotates continuously in the direction of the arrow.
Moved and stored in the pocket 1a of the turret 1, reaching the foot 1b to the main turret 2, and the arrow A
Pocket of main turret 2 continuously rotating in two directions
a (can transfer up to about 1500 cans per minute).

In the main turret 2, the seamless can 4 having the pre-neck portion 4'g and the pre-flange portion 4'h formed into the neck-in portion 4g and the flange portion 4h (see FIG. 2) is arranged in the direction of the arrow. In the feeding section 2b to the reject turret 3, which rotates continuously, the can 4 which is footed in the pocket 3a of the reject turret 3 and the defective portion is detected is rejected by the reject section 3b, and the normal can 4 is sent to the sending section 3c. To a turret (not shown) of another process. The foot ゛ portion 1b and the sending portion 2b are located at positions 60 ° and 300 ° in the direction of arrow A, respectively, starting from a position S (0 °) immediately below the axis of the main shaft 2c of the main turret 2.

Each pocket 2a of the main turret 2 is provided with a seamless can shaping device 5 shown in FIG. The shaping device 5 includes a bottom support 6, a shaping tool device 7 disposed opposite to the bottom support 6, and concentric with the bottom support 6.
And a can body receiver 8. In this specification, the side of the bottom support 6 that faces the shaping tool device 7 is called a front portion, and the side of the bottom support 6 that is close to the shaping tool device 7 is called a front portion. The bottom support 6 includes a slide 11 slidable in the axial direction through a through hole of a wheel 10 (which constitutes a part of the main turret 2) fixed to the main shaft 2 c, a center shaft 12 at a fixed position in the axial direction, and a slide. 11 has a bottom chuck 13 slidably provided at a front end portion thereof and a bottom pad 14 slidably mounted along a front end portion 12c of the center shaft 12.

The slide 11 is slidable along a relatively large-diameter main portion 12a of the center shaft 12 via a bushing 15. A cam roll (not shown) that engages with a cam groove formed in a fixed frame (not shown) is provided at a rear portion of the slide 11. The cam groove is formed so that the slide 11, and thus the bottom chuck 13 advances, stops and retreats at the timing shown in FIG. 3 as the main turret 2 rotates. A coil spring 16 is provided inside the cylindrical space 17 formed by the inner surface of the slide 11, the outer peripheral surface of the middle diameter portion 12b of the center shaft 12, and the base 13a of the bottom chuck 13. Further, a spacer 18 for adjusting the spring strength of the coil spring 16 is provided inside the bottom of the space 17. A step 13e extending radially outward is formed on the outer peripheral surface of the bottom chuck 13 facing the intermediate inner peripheral surface 13c, and the step 13e is formed with the inner surface 11a of the inner flange provided at the tip of the slide 11. , Are always engaged under the pressure of the spring 16. Therefore, the bottom chuck 13 is
Forward and backward with. In the engaged state, a slight gap 9 is formed between the step 13f on the back of the step 13e of the bottom chuck 13 and the step 11b on the back of the step 11a of the slide 11.

A front end portion 12c of the center shaft 12 has a small diameter portion, and a washer 19 is fixed to an end surface thereof with a bolt 20. A vacuum hole 21 passes through the bolt 20, the washer 19, and the center shaft 12, and the vacuum hole 21 is connected to a vacuum source (not shown) via a vacuum valve (not shown). A ring 24 for adjusting the axial position of the bottom pad 14 is provided in close contact with the step at the front end of the middle diameter portion 12b of the central shaft 12. The bottom pad 14 is
A main portion 14a slidable along the bottom inner peripheral surface 13b of the bottom chuck 13 and a thick flange portion 14b that can be inserted almost exactly into the intermediate inner peripheral surface 13c of the bottom chuck 13 are provided.
A coil spring 23 is provided in a cylindrical space 22 mainly formed by a relatively small-diameter bottom side hole 14 c of the bottom pad 14, a center shaft tip 12 c and a washer 19. The outer diameter of the end surface 14b1 of the flange portion 14b is set slightly larger than the outer diameter of the ground portion 4'a at the bottom of the seamless can 4 '.
It can be placed on b1.

A stop period after the bottom chuck 13 advances (between 114 degrees and 239 degrees in FIG. 3), and a period before and after each stop period
Except for 3 degrees, the rear surface 14e of the bottom pad 14 is in close contact with the ring 24 under the pressure of the spring 23. Therefore, when the seamless can 4 'is accommodated in the pocket 2a (60 degrees), the flange end face 14b1 of the bottom pad is in the position shown in FIG.
It is in the position shown. A step 13g is formed between the inner peripheral surfaces 13b and 13c of the bottom chuck 13. A step 14f is also formed on the rear surface of the flange portion 14b of the bottom pad. When the bottom chuck 13 moves forward together with the slide 11, just before the end of the forward movement (114 degrees in FIG. 3) (101)
At this time, the step 13g and the step 14f are engaged (FIG. 2). In this engagement state, the base 13a of the bottom chuck 13 and the rear surface 1 of the bottom pad 14
A slight gap 34 remains between 4e. When the slide 11 further advances, the bottom pad 1 is attached to the bottom chuck 13.
Forward movement continues with 4 engaged. The inlet side inner peripheral surface 13d of the hole of the bottom chuck 13 has a shape and dimensions that allow the chime portion 4'b at the bottom of the seamless can 4 'and the lower body portion 4'c1 in the vicinity thereof to be inserted exactly. (See FIG. 2).

The shaping tool device 7 includes a wheel 25 (a part of the main turret 2) fixed to the main shaft 2c.
The slide 26 is slidable in the axial direction through the through hole and a central shaft 28 slidable along the bushing 27 through a through hole 26a (FIG. 2) of the slide 26. A ring-shaped reform die 2 is provided at the tip of the slide 26.
9. A shim 31 for adjusting the axial position of the retainer 30 and the reform die 29 is fixed. At the tip of the center shaft 28, a reform flange die 32 is fixed inside the reform die 29 so as to substantially face the reform die 29. The outer peripheral surface of the re-flange die 32 has a chamfered portion 32a at the tip, a cylindrical portion 32b, a curved portion 32c1 connected to the base of the cylindrical portion 32b, and an extremely narrow flat portion 32c2 extending substantially in the radial direction.
c (see FIG. 7). The flat portion 32c2 may be slightly obliquely outward and upward (as viewed from the direction of FIG. 7), and the angle of the flat portion 32c2 with the radial direction is preferably 0 to 5 degrees.

The outer diameter of the cylindrical portion 32b is set to a size that defines the inner diameter of the neck 4f (see FIG. 7) after reforming. The re-flange surface 32c has a shape and dimensions that define the outer surface of the flange portion 4h after reforming.
In order to slightly protrude from the outer end of the riflange surface 32c,
A re-flange ring 33 is mounted on the central shaft 28.
The inner surface 33a of the distal end cylindrical portion of the re-flange ring 33 comes into contact with the end of the pre-flange portion 4'h at the time of re-flanging, and serves to determine the width of the formed flange portion 4h to a predetermined value.

The inner diameter of the retainer 30 is a seamless can 4 '.
Is slightly larger than the outer diameter of the body 4′c.
The reform die 29 has a trapezoidal front processing surface 29a and a rear processing surface 29b whose diameter decreases toward the rear. The inner diameter of the front end portion 29a1 (see FIG. 5) of the front processing surface 29a is set slightly larger than the inner diameter of the retainer 30. The angle α (for example, about 158 to 175 degrees) between the front processed surface 29a and the rear processed surface 29b is
Of the body 4′c and the shoulder 4′e (eg, about 145)
１５155 °). Front processing surface 2
9a and the rear processing surface 29b may directly intersect, or may be connected via a curvature portion having a small radius of curvature (for example, about 8 to 20 mm). The angle θ between the front processing surface 29a and the axis is preferably 3 to 10 degrees, and the rear processing surface 29b
Is preferably 15 to 25 degrees. It is preferable that the length of the vertical section straight portion of the front processed surface 29a is 3 to 10 mm, and the length of the vertical section linear portion of the rear processed surface 29b is 0 to 5 mm.

When shaping a seamless can 4 'having a nominal body diameter of # 211 (66 mm) and a nominal neck-in diameter of # 206 (57.4 mm), the front processing surface 29a and the rear processing surface 2
9b has an angle α of 170 degrees, and the trunk 4′c and the shoulder 4′e
Is greater than 152 degrees, the length of the straight portion of the front processed surface 29a is 9 mm, the length of the straight portion of the rear processed surface 29b is 3.2 mm, and the front processed surface 29a and the rear processed surface 29 are formed.
b is connected via a curvature portion having a curvature radius of 15 mm, the angle θ between the front processing surface 29a and the axis is 7.5 degrees, and the angle δ between the rear processing surface 29b and the axis is 17 degrees. 0.5 degrees. Under the above conditions, when the radii of curvature of the curvature portion are 8 mm and 20 mm, the lengths of the straight portions of the rear processed surface 29b are 4.3 mm and 2.4 mm, respectively, and as the curvature radius of the curvature portion increases, Rear processing surface 29b
Becomes shorter. When the angle δ between the rear processing surface 29b and the axis line increases, for example, 23.5 degrees or more,
If the radius of curvature of the curvature portion is 20 mm, the rear processing surface 29
The length of the straight part of b is 0 mm, and the rear processing surface 29b
Is formed only by a concave circular arc portion in a vertical section. Angle δ in this case
Is the angle between the tangent and the axis at the end of the arc.
Then, the portion of the curvature portion rearward from the intersection of the intersection of the extension line of the tangent and the extension line of the front processing surface 29a and the straight line connecting the center of the curvature portion is regarded as the rear processing surface 29b. Similarly, when there is a curvature portion between the front processing surface 29a and the rear processing surface 29b, the front processing surface 29a and the rear processing surface 29a
b, a straight line connecting the intersection of the respective extension lines and the center of the curvature portion, and a curvature portion in front of a point where the curvature portion intersects is regarded as a part of the front processing surface 29a, and a curvature portion behind the point is defined as a rear portion. It is regarded as a part of the processing surface 29b.

At the rear of the central shaft 28, a cam roll (not shown) is mounted to engage with a cam groove formed in a fixed frame (not shown). The cam groove is formed so that the central shaft 28 and thus the re-flange die 32 advance, stop and retreat at the timing shown in FIG. 3 as the main turret 2 rotates. At the rear of the slide 26, a cam roll (not shown) that engages with a cam groove formed in a fixed frame (not shown)
Has been installed. With the rotation of the main turret 2, the cam groove moves the slide 26 and thus the reform die 2.
Reference numeral 9 is formed so as to advance, stop, and retreat at the timing shown in FIG.

The seamless can 4 'in this embodiment is manufactured, for example, as follows. Surface treated steel plate such as tin-free steel (for example, 0.18 thick
mm) on both sides of a polyester film (e.g.
0 μm).
Drawing-thinning re-drawing (for example, see JP-A-1-258
No. 822, using a die having a processing corner with a small radius of curvature). 'a and chime part 4'
After forming b, the pre-necked-in portion 4'g and the pre-flanged portion 4'h are formed by a roll foam method as shown in FIG. Nominal can diameter is usually # 202 (body diameter 53
mm)-# 211 (body diameter 66 mm), can height is about 80-1
35 mm, average thicknesses of the trunk and bottom are about 0.10 to 0.21 mm and about 0.16 to 0.26 m, respectively.
m. However, the seamless can 4 'of the present invention is not limited by the above-mentioned manufacturing method, size, and the like.

The reforming of the pre-necked portion 4'g of the seamless can 4 'and the re-flanging of the pre-flanged portion 4'h by the shaping device 5 are performed as follows. In this specification, the reform die 29
For the re-flange die 32, the movement of the bottom support 6 in the direction (to the right in FIG. 2) is called forward, and the reverse is called retreat. The movement of the bottom chuck 13 and the bottom pad 14 in the direction of the shaping tool device 7 (to the left in FIG. 2) is called forward, and the reverse is called retreat. The positions of the bottom support 6 and the shaping tool device 7 in FIG. 2 are referred to as original positions.

As shown in FIG. 3, the vacuum valve of each pocket 2a opens at a timing angle (hereinafter simply referred to as "degree") of 45 degrees and is turned on. At the time of 60 degrees, the seamless can 4 ′ transferred by the transfer turret 1, the outer guide and the side guide (not shown) becomes the can body receiver 8 in the pocket 2 a of the main turret 2 continuously rotating in the direction of arrow A. (Figure 2,
State). At this point, the ground 4'a is
Is about 2 mm away from the end face 14b1 of the first embodiment. Figure 3,
Immediately, the re-flange die 32, the reform die 29, and the slide 11, that is, the bottom chuck 13, immediately start moving forward. Just before 105 degrees, the step 13g of the bottom chuck 13 and the step 14f of the bottom pad 14
And the bottom pad 14 comes into contact with the ground portion 4'a at 105 degrees (FIG. 4).

At 114 degrees, the bottom chuck 13 and the bottom pad 14 reach the most advanced position and stop (see FIG. 4). In the meantime, the bottom of the seamless can 4 ′ is suctioned under vacuum, the ground portion 4 ′ a is suctioned to the flange end surface 14 b 1 of the bottom pad 14, and the chime portion 4 ′ b comes into close contact with the inlet side inner peripheral surface 13 d of the bottom chuck 13. (See FIG. 4). As shown in FIGS. 4 and 5, at an angle of 105 degrees, the upper end 4'c2 of the body of the seamless can 4 'starts to contact the retainer 30, and the neck 4'f contacts the cylindrical portion 32b of the re-flange die. Begin to. Angle from 118 degrees to 14
At the time between five degrees, the re-flange die 32 pauses,
Centering (concentric) of the seamless can 4 'is performed. During this centering, the reform die 29
The reforming starts at the time of 20 degrees (FIG. 4), and then proceeds forward, and ends at the time of 130 degrees (FIG. 4).

At the time of 130 degrees, as shown in FIG.
The upper end 4'c2 of the trunk portion and the lower half of the curved portion 4'd are in close contact with the front processed surface 29a, and the upper half of the curved portion 4'd and part of the shoulder 4'e are rear processed surfaces 29b. Is close to
The curved portion 4'd is plastically deformed, and the lower portion of the upper end 4'c2 of the trunk portion and the lower portion of the shoulder 4'e are elastically deformed. The reform die 29 is paused between 130 and 135 degrees, and retracts slightly (for example, about 0.5 mm) between 135 and 145 degrees. By this retreat, as shown in FIG. 7, the elastic deformation of the upper and lower portions of the curved portion 4'd, which are in close contact with the front processed surface 29a and the rear processed surface 29b, is released. The front processing surface 29a and the rear processing surface 29b lightly contact with each other in a state in which the 4'd and the shoulder 4'e have an inverted bowl shape as a whole. This inverted bowl-shaped portion becomes the shoulder 4e of the neck-in portion 4g of the shaped seamless can 4. This retraction helps to reduce the molding load during riflange processing.

The reform die 29 is stopped from 145 degrees to 230 degrees. Meanwhile, re-flange die 32
Resumes advance at 145 degrees and continues to advance to 185 degrees. During this forward movement, the neck 4'f
2b is shaped so as to obtain concentricity between the roundness and the body 4′c. At the time of 185 degrees, the re-flange surface 32c of the re-flange die 32 of the pre-flange portion 4'h
Thus, the seamless can 4 is formed (see FIGS. 2 and 7). Variations in the width of the pre-flange portion 4'h are corrected by the re-flange ring 33 as follows. In other words, the portion where the width of the preflange portion 4'h is long reaches the inner surface 33a of the distal end cylindrical portion of the re-flange ring 33 by the advancement of the central shaft 28, and the molding is finished. It is corrected by continuing the molding by moving forward. Since the axial load applied to the seamless can 4 'during re-flanging is relatively large (for example, about 500 kgf), if there is a seamless can 4' whose can height is higher than the reference value,
Although buckling may occur, the spring 16 of the bottom support 6 may be used.
This buckling is unlikely to occur because of the buffering effect of Note that the axial load applied to the seamless can 4 'during the reforming process is smaller than that during the re-flanging process.

The re-flange die 32 is provided at a position between 185 degrees and 19 degrees.
Pause until 0 degree, then start retreat, 26
It returns to its original position at 0 degrees. On the other hand, since the reform die 29 is stopped up to the point of 230 degrees, when the cylindrical portion 32b passes through the neck 4f due to the retreat of the reflange die 32, it serves as a stopper for the seamless can 4.
The reform die 29 starts retreating at 230 degrees and returns to the original position at 300 degrees. Bottom chuck 13
Is the first time the reform die 29 has retreated 239
At the time of the degree, the retreat is started, and while the vacuum of the bottom of the seamless can 4 is suctioned, the seamless can 4 is retreated and returns to the original position at the time of 297 degrees. The vacuum in the vacuum hole 21 is released at the time of 300 degrees, at which point the seamless can 4 moves to the reject turret 3.

The present invention is not limited by the above-described embodiments. For example, the front processed surface and / or the rear processed surface may have a slightly convex or concave curved cross section as a whole.

[0029]

According to the present invention, a pre-necked portion of a seamless can formed by a roll foam method is used for a neck portion having excellent roundness and concentricity with a body portion, and a shoulder portion having improved axial load strength. The pre-flange can be shaped into a flange portion having a uniform width and suitable for double winding. The invention according to claim 2 has an advantage that the pre-necked portion can be shaped into a necked-in portion having a shoulder having excellent dent resistance. The invention according to claim 3 has an advantage that buckling of the seamless can can be prevented during the shaping process.

[Brief description of the drawings]

FIG. 1 is an explanatory front view of an example of a turret on which an apparatus for carrying out the method of the present invention is mounted.

FIG. 2 is a longitudinal sectional view of an example of an apparatus for performing the method of the present invention, showing a state at a time of 60 degrees when a seamless can to be shaped is supplied; Is a diagram showing a state at the time of 185 degrees at which is completed.

FIG. 3 is a timing chart showing the movement of each movable part of the apparatus shown in FIG. 2 and the opening and closing of a vacuum valve.

FIG. 4 is a view showing the movement of a reform die and a bottom pad until the reform of the pre-necked-in portion of the seamless can is completed by the apparatus of FIG. 2;
The drawing showing the state at the time of 5 degrees, the drawing showing the state at the time of 120 degrees, and the drawing showing the state at the time of 130 degrees.

FIG. 5 is an enlarged vertical sectional view of a main part at 105 degrees, showing a process of reforming a pre-necked-in portion by the apparatus of FIG. 2; The angle α formed by the processing surface (dotted line)
It is a drawing including a figure showing the relation of angle β which a shoulder part of a pre-neck in part and a trunk part make.

FIG. 6 is an enlarged longitudinal sectional view of a main part showing a state at a time of 130 degrees when the reforming of the pre-neck-in part is completed by the apparatus of FIG. 2;

FIG. 7 shows a state (solid line) at 135 degrees when the reforming die is slightly retracted from the state shown in FIG. 6, and a state (1) at 185 degrees when re-flanging is completed.
It is a principal part enlarged longitudinal cross-sectional view showing a dashed line).

FIG. 8 is a longitudinal sectional view showing an example of a state immediately after a pre-necked-in portion and a pre-flanged portion of a seamless can to be shaped are formed.

[Explanation of symbols]

 4 Seamless can (after shaping) 4g Neck-in part 4h Flange part 4 'Seamless can (before shaping) 4'a Grounding part 4'b Chime part 4'c Body 4'd Curved part 4'e Shoulder part 4 'f Neck 4'g Pre-necked part 4'h Pre-flanged part 13 Bottom chuck (chuck) 13d Inlet side inner peripheral surface (inner peripheral surface) 14 Bottom pad 16 Coil spring (spring) 23 Coil spring (spring) 29 Reform Die 29a Front processing surface 29a1 Front end portion 29b Rear processing surface 32 Riflange die 32b Cylindrical portion 32c Riflange surface 32c1 Curvature portion 32c2 Flat portion 33a Riflange ring tip cylindrical portion inner surface (step)

Claims (3)

(57) [Claims] 1. A pre-necked-in portion including a curved portion connected to a body portion, a trapezoidal shoulder connected to the curved portion, and a neck connected to the shoulder, and an inverted trapezoidal pre-flanged portion connected to the neck. In the method of shaping the pre-necked-in part and the pre-flanged part of the seamless can having the bottom part of the seamless can fixed to the chuck, and the neck inner surface is brought into close contact with the outer peripheral surface of the cylindrical part of the riflange die concentric with the chuck. The inner diameter of the front end is slightly larger than the outer diameter of the body of the seamless can, and the reforming die having a trapezoidal front processed surface and a rear processed surface that is expanded forward is advanced, and the front processed surface and The curved portion and its vicinity are mainly pressed inward in the radial direction by the rear processed surface, and the curved portion and its nearby portion are plastically deformed along the front processed surface and the rear processed surface, Next, the reforming die was slightly retracted to remove the elastic deformation of the plastically deformed curved portion and its vicinity, that is, the elastic deformation of the portion close to the front processed surface and the rear processed surface, except for the curved portion near the curved portion of the body portion and the curved portion. And, when the shoulder is in the shape of an inverted bowl as a whole, the riflange die is advanced to comprise a curvature portion connected to the base of the cylindrical portion of the riflange die and a flat portion extending substantially in the radial direction, and the distal end extends forward. A method for shaping a seamless can, characterized in that a pre-flange portion is pressed by a re-flange surface defined by a step portion to form a substantially radially extending flange portion. 2. The angle α between the front processed surface and the rear processed surface of the reform die is the angle β between the body and the shoulder of the seamless can.
The method for shaping a seamless can according to claim 1, which is larger. 3. The bottom of the seamless can has a chime portion and a ground contact portion, and the chuck has an inner peripheral surface into which the chime portion can be inserted exactly, and in a state where the chime portion is inserted into the chuck. 3. The method according to claim 1, wherein the ground portion is placed on the bottom pad, and when the pre-flange portion is pressed by the re-flange surface, the chuck and the bottom pad are buffered by a spring.