JP2705572B2 - Manufacturing method of squeeze cup - 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 producing a squeezing cup used for forming a can, such as a can of carbonated beverage can, beer can, coffee beverage can, fruit beverage can and the like.

[0002]

[Prior Art] Tin-free steel, tinned steel sheet,
A relatively long and thin seamless can suitable for storing beer, carbonated beverage, etc., which is composed of a laminate obtained by thermally bonding a biaxially stretched polyester film 7 (see FIG. 10) to a metal plate 6 for a can, such as an aluminum (alloy) thin plate, is proposed. (For example, Japanese Patent Application Laid-Open No. 3-71938). In this type of seamless can 22 (FIG. 9), a circular blank is punched out from the above-mentioned laminate by a cupping machine and simultaneously drawn to form a drawn cup, and the drawn cup is thinned and redrawn by a transfer press. After ironing or further ironing, the bottom is domed to form an annular projection 22a1 serving as a grounding portion, and then a neck-in portion 22c is formed.
It is manufactured through a process such as formation of the flange portion 22d.

[0003] The thus-produced seamless can 2
2 (FIG. 9) shows that although the degree of processing at the bottom is relatively small, the body 2
The working ratio of 2b is relatively large, and the working ratio increases as approaching the opening end. This kind of conventional seamless can 22
The degree of biaxial orientation of the polyester film of the blank used to form the film was uniform over the entire area. For this reason, when a blank with a high degree of biaxial orientation is used so that the polyester film does not crack even when the annular protrusion 22a1 at the bottom is dented, for example, when dropped in a canned state, the degree of processing is high. The degree of orientation (stretching degree) of the polyester film in the body becomes too high, so that the adhesion is reduced and the polyester film is easily peeled. Therefore, especially when the content liquid is a highly corrosive drink such as cola or lactic acid bacteria drink, the metal is eluted in the content liquid, and the flavor is damaged, or discoloration occurs (in the case of lactic acid bacteria drink, yellowing) occurs. It is easy to reduce product value. On the other hand, when a blank with a small degree of biaxial orientation is used to the extent that the adhesion of the body is not reduced, when dropped, the annular protrusion at the bottom is dented, and the polyester film is easily cracked, and similarly, Cause problems.

[0004]

In order to prevent such troubles, the degree of orientation of the polyester film in the peripheral portion corresponding to the body portion is more than that in the center portion of the circular blank corresponding to the bottom portion of the seamless can and the vicinity thereof. It may be preferable to use a blank with a small. In the case of industrial mass production, portions 2 to be circular blanks of the type described above are formed in the longitudinal direction of the web at small intervals, preferably in rows, as shown in FIG. It is desirable that the portion 2 be stamped and drawn. However, the part 2 to be this circular blank
Has no apparent difference from other parts, and cannot be visually identified. Even if it is identifiable (for example, when a portion that should become a circular blank is printed)
Feeding the part to be a circular blank directly beneath the punch of the cupping machine so that it can be punched substantially accurately requires slippage between the web and the feed roll at the time of feeding, thermal expansion of the web, and the like. Happened and was difficult.

The present invention is directed to intermittently forming a web at high speed (eg, an average of 75 m / min.) So that the portion of the metal web to be formed into a drawing cup is substantially exactly below the punch of the cupping machine. 250 shots / min) to provide a method for producing a squeeze cup.
Subject. The present invention further comprises a biaxially stretched polyester film peeled off from the web made of a laminate which is thermally bonded to a metal strip, from the biaxially stretched polyester film of the trunk,
A second object of the present invention is to provide a method for producing a drawing cup for forming a seamless can at a high speed, in which a crack in the biaxially stretched polyester film at the bottom and in the vicinity thereof hardly occurs.

[0006]

According to a first aspect of the present invention, there is provided a method for manufacturing a drawing cup, comprising: a feed roll having a rigid pressing roll and a driving roll having an outer peripheral portion formed of an elastic sleeve. A method of intermittently feeding a metal web into a cupping machine by a device, punching a blank with a punch, drawing and forming a drawing cup, wherein a rotation angle of a driving roll at every feeding is fixed. Based on the shift length of the gauge mark provided at the interval L equal to the predetermined feeding length in the longitudinal direction of the metal web from the reference position detected by the image sensor at the stop timing, The pressing force of the driving roll against the elastic sleeve is adjusted to adjust the feeding length of the metal web after the stop timing, and the imaginary line in the width direction passing through the gauge mark is adjusted. The axis of the punch, characterized in that the shaping aperture aligned so as to lie substantially.
In this specification, the elastic sleeve refers to a sleeve made of an elastic body whose volume does not substantially change by compression,
The elastic body specifically refers to an elastic rubber or an elastic plastic which is entirely solid without bubbles and does not include a foamed elastic rubber or the like.

According to a second aspect of the present invention, there is provided a biaxially oriented polyester film which is formed by laminating a biaxially stretched polyester film to a metal strip by heat bonding, and the biaxially stretched biaxially oriented polyester film is formed at a central portion of a portion to be punched as a blank. 2. A method of manufacturing a drawing cup according to claim 1, wherein a web having a degree of orientation higher than the degree of biaxial orientation of a peripheral portion and having a gauge mark on an imaginary line in a width direction passing through the center of the portion to be punched is used. It is what you do.

[0008]

As shown in FIG. 6, the metal web feed roll device 9 includes a rigid press roll 10 and a drive roll 11 having an outer peripheral portion formed of an elastic sleeve 11y. Since the sleeve 11y constituting the outer peripheral portion of the driving roll 11 is made of an elastic material, when pressed by the rigid pressing roll 10, the portion facing the pressing roll 10, that is, the web 1
The portion 11y 'that contacts the dent is concave in an arcuate cross-section, and a bump-like ridge 25 is formed on both sides of the dent. Since the web 1 is fed by the drive roll 11 along the ridge 25, the apparent radius that determines the feed length of the drive roll 11 is as follows:
R1 is slightly larger than the true radius R. Ridge 2
5, and thus the apparent radius R1 increases as the pressing force increases. The feed length of the web 1 with respect to the rotation angle (rotation amount) of the drive roll 11 is proportional to the apparent radius R1 of the drive roll 11.

Therefore, even if the rotation angle of the drive roll 11 at each time of feeding is constant, the pressing length of the rigid pressing roll 10 against the elastic sleeve 11y can be adjusted to adjust the feeding length of the web 1. . The pressing force can be adjusted in a short time and precisely by adjusting the air pressure of the air cylinder (14), for example. Therefore Web 1
To feed the web 1 into the cupping machine 8 at high speed and intermittently, precisely adjusting the feeding length of each time, even if it is relatively heavy and has a large inertial force, mainly composed of a metal band. Can be. A method of changing the rotation angle (rotation amount) of a conventional driving roll of a driving roll per rotation by a servo motor or the like can be considered, but when the inertia force of the web is large,
It has been found that it is extremely difficult to accurately adjust the length of each time the web is fed intermittently at high speed in such a manner and feed the web into the cupping machine 8. Based on the shift length of the gauge mark provided at the interval L equal to the predetermined feeding length in the longitudinal direction of the metal web from the reference position detected by the image sensor at the stop timing, the metal web after the stop timing Is adjusted so that the axis of the punch is substantially positioned on an imaginary line in the width direction passing through the gauge mark, and the drawing is performed.
The draw cup can be manufactured by intermittently feeding the web such that the portion of the metal web to be formed into the draw cup is substantially exactly below the punch of the cupping machine.

In the case of the invention according to claim 2, since the gauge mark 4 is provided on an imaginary line in the width direction passing through the center 2a of the portion 2 to be punched, the center of the portion to be punched and the axis of the punch are set. Can be formed so as to substantially coincide with each other. Metal web 1
Consists of a laminate (see FIG. 10) in which a biaxially stretched polyester film 7 is thermally bonded to a metal strip 6, and the degree of biaxial orientation at the center of a portion to be punched out as a blank is smaller than the degree of biaxial orientation at the periphery. Because of the high cost, the seamless can 22 manufactured from the squeezing cup 21 is unlikely to cause peeling of the polyester film 7 of the body 22b and cracking of the polyester film 7 at the bottom 22a and the vicinity thereof.

[0011]

FIG. 1 shows a metal plate 6 for a can (see FIG. 9), for example, tin-free steel having a thickness of about 0.1 to 0.4 mm;
This shows a web 1 formed by thermally bonding a biaxially stretched polyester film 7 (see FIG. 10) having a thickness of about 10 to 30 μm to both sides of a metal strip such as a tin-plated steel sheet or an aluminum (alloy) thin plate. . If necessary, an adhesive primer may be interposed at the time of thermal bonding. The circular portions 2 indicated by dashed lines, which are arranged in a plurality of rows (six rows in the present embodiment) in the shape of a goose approaching each other in the longitudinal direction, are punched out simultaneously by a cupping machine 8 to form a blank 3 (FIG. 2). Here are the parts to be done. Center 2 of circular part 2 of each row separated by one row
a is located on the same imaginary line perpendicular to the feeding direction A of the web 1, and is, for example, a black gauge mark 4 (for example, a rectangle having a side length of 1 mm × 5 mm) on the imaginary line at the edge of the web.
Is applied by an ink-jet method or the like. Circular part 2
Is 180 mm in the present embodiment, and the width d of the narrowest portion of the bridge portion 5 which is a gap between the circular portions 2 in each row is 0.8 mm. Therefore, the distance L between the adjacent gauge marks 4 is equal to D + d (= 180.8 mm),
The width of the web 1 is about 1 m. In FIG. 1, the gauge marks 4 are provided on both sides of the web 1 because coil winding may be performed when the web is in a coil shape (see paragraph 0014). The width d is desirably as small as control permits, in order to maximize the number of blanks 3 produced per unit area of the web 1.
Accordingly, since the width d is extremely small, even if the alignment at the time of punching is slightly out of order, there is a possibility that a defective product such as a missing circular blank may appear.

As shown in FIG. 2, the blank 3, that is, the circular portion 2 includes a central portion 2b, an intermediate portion 2c, and a peripheral portion 2d having a diameter of about 0.5D. The degree of biaxial orientation Rx of the laminated biaxially stretched polyester film is large at the central portion 2b (for example, about 4 and small at the peripheral portion 2d (for example, approximately 2), and is small at the intermediate portion 2c from the central portion 2b side to the peripheral portion. The biaxial orientation degree Rx is approximately 0.34 nm, which is parallel to the polyester surface of the web 1 (CuKα X-ray diffraction angle is 2).
The diffraction intensity Ia by the diffraction plane of 4 degrees to 28 degrees) is set to about 0.39 nm (Cu
(Kα X-ray diffraction angle is 21.5 degrees to 24 degrees) and is defined by a value Ia / Ib divided by a diffraction intensity Ib by a diffraction surface.

As polyester for the polyester film, polyethylene terephthalate polyester,
In particular, an ethylene terephthalate / isophthalate copolymer (for example, a molar ratio of 88/12; a crystal melting point of about 227 ° C .; a glass transition point of about 75 ° C.) is preferably used. For example, when the biaxially stretched polyester film is thermally bonded, the web 1 has a portion corresponding to the central portion 2b of the metal strip at a relatively low temperature and a portion corresponding to the peripheral portion 2d at a relatively high temperature. (For example, the portion corresponding to the central portion 2b is 220
℃, the part corresponding to the peripheral part 2d is 230 ℃)
Alternatively, after the biaxially stretched polyester film is thermally bonded to the metal strip, the biaxial orientation is relaxed by heating only the portion corresponding to the peripheral edge portion 2d and the portion that becomes a chip outside the peripheral portion.

The web 1 is supplied in the form of a coil (about 10 tens of tons) and mounted on an uncoiler (not shown) in the cupping line. The web 1 is fed from an uncoiler through a looper (not shown) to a cupping machine 8 shown in FIGS. As shown in FIG. 3, the cupping machine 8 includes a crankshaft 8a, a crank 8b, a slide 8c, a plurality of (six in this embodiment) punches 8d, a die set 8e, and a bolster 8f. The punch 8d includes, for example, six circular portions 2 indicated by oblique lines in FIG. 1, that is, three circular portions 2x and a circular portion 2x at the same position in the width direction of the first, third, and fifth columns from the left side of the drawing. The second, fourth and fourth parts sandwiched on the lower side by the lower circular part 2 of the adjacent drawing
The three circular portions 2y in the sixth row are arranged so as to be punched out simultaneously and drawn (FIG. 4).

As shown in FIG. 3, the feed roll device 9 includes:
A pressing roll 10 and a driving roll 11 are provided. As shown in FIG. 5, the pressing roll 10 includes a body 10a made of a hollow rigid pipe, for example, a steel pipe and a shaft 10a.
b, the shaft 10b is
Is supported by Each bearing 12 is mounted on a piston rod 15 of an air cylinder 14 fixed to a fixed frame 13, and can change the pressing force on the drive roll 11 by changing the air pressure of the air cylinder 14. It has become. The air cylinder 14 is connected via a conduit 16 and an air pressure regulator 19 to a source of pressurized air 20 (FIG. 4).

As shown in FIG. 5, the drive roll 11 has a rigid pipe 11x having an inner peripheral portion made of, for example, steel, a body portion 11a having an outer peripheral portion made of an elastic sleeve 11y, a shaft 11b, and a drive gear fixed to the shaft 11b. 11
c. In this embodiment, the elastic sleeve 11y is made of urethane rubber having a Shore hardness A of about 90 and a thickness of 3 mm. The drive gear 11c is connected to the crankshaft 8
An indexer (indexing device) connected to the drive mechanism a
And a gear (not shown) provided at the end of the output shaft, and rotates by a fixed angle θ every rotation of the crankshaft 8a, ie, every stroke of the punch 8d. Is determined so that the feed roll device 9 feeds the web 1 in the length A in the direction L under the reference pressing force F described later.

On the upstream side of the cupping machine 8, a CCD camera 17 having a built-in image sensor 17a is provided with a reference detection position 17b (FIG. 7) of the image sensor 17a and a center line of a row of punches on the downstream side of the cupping machine 8. The distance p between 8g is nxL (n is an integer: n = 5 in this embodiment, p = 5L; see FIG. 1), and the gauge mark 4 at the timing when the web 1 stops for punching and drawing. (FIG. 4). A light projector 24 for irradiating the gauge mark 4 is provided near the CCD camera 17. The output signal of the image sensor 17a is input to the air pressure controller 19 via the sequencer 18.

The feeding of the web 1 into the cupping machine 8 and the manufacture of the squeezing cup 21 are performed as follows by the above-described apparatus. The elastic sleeve 11y of the drive roll 11 is always pressed to the reference pressing force F by the pressing roll 10.
(1.0 ton in the present embodiment), as shown in FIG. 6, the portion facing the pressing roll 10, that is, the portion 11y 'in contact with the web 1 is recessed in an arc-shaped cross section, A bump-like raised portion 25 is formed on both sides of the drive roll 11, and an apparent radius when the drive roll 11 is fed is R1. The apparent radius R1 increases with the pressing force. The feed length of the web 1 with respect to the rotation angle θ of the drive roll 11 is proportional to the apparent radius R1, and therefore increases as the pressing force increases. The reference pressing force F is determined so that the feed length per operation is L. When the pressing force increases by ΔF, the feed length of the web 1 at one time increases by Δp1 / m (m is an integer, preferably about 10 to 30: see FIG. 7). In the present embodiment, the feed length per operation in the case of the reference pressing force F is 180.8 mm, and when the pressing force increases by 125 kg with respect to the reference pressing force F, the feed length becomes 0.2.
mm.

FIG. 7 shows that the center 2a of the circular portion 2 of the web 1 to be punched is Δp1 from the center of the downstream punch 8d.
This shows an example of an image image by the image sensor 17a when the web 1 is located upstream of the feeding direction A by, for example, 1 mm, that is, when feeding of the web 1 is delayed by Δp1. The center of the gauge mark 4 is located upstream of the detection reference position 17b of the image sensor 17a by a distance of Δp1. Based on the signal from the image sensor 17a, the sequencer 18 detects the value of + Δp1 and outputs a signal for increasing the pressing force by ΔF to the air pressure controller 19. Therefore, the pressing force of the pressing roll 10 increases by ΔF to become F + ΔF, and the feed length immediately after the detection is L
+ Δp1 / m (m is, for example, 20). This process is called m
Repeat it. During this time, the detected value changes, and each time the pressing force changes based on the signal from the sequencer 18,
F and Δp1 decrease. Therefore, the feed length changes,
The delay of length Δp1 is recovered, and the pressing force becomes the standard pressing force F
Then, punching is performed in a state where the gauge mark 4 is substantially on the center line 8g, and drawing is performed. When the gauge mark is at the position indicated by 4 'in FIG. 7, the sequencer 18 detects the signal of -.DELTA.
The pressing force of 0 decreases by ΔF, and the feed length immediately after detection is L-
Δp 2 / m, and Δp 2 does not advance in the same manner as described above, and the gauge mark 4 is punched out and substantially drawn in a state where it is substantially above the center line 8 g.

On the cupping machine 8, an iris cup 21 is formed as shown in FIG. Squeeze cup 21
The bottom portion 21a of the blank 3 is substantially the center portion 2b of the blank 3, the curvature corner portion 21b and the vicinity thereof are rougher than the intermediate portion 2c, and the side wall portion 21c is the peripheral edge portion 2d. The squeezing cup 21 is then transferred by a transfer press.
No. 258822, thinning and redrawing are performed by a method as described in JP-A-258822, or ironing is further performed.
Is formed in a seamless can (not shown) having a bottom 22a (see FIG. 9) having After the outer surface printing is performed on the body portion 22b, the seamless can is formed with the neck-in portion 22c and the flange portion 22d, and becomes the seamless can 22 shown in FIG.

The present invention is not limited by the above embodiments. For example, the web may be a metal strip directly printed on a metal strip corresponding to a circular portion. The blank may have a shape other than a circle such as a square. The pressing force of the pressing roll against the driving roll may be adjusted by appropriate means such as by controlling the displacement of the pressing roll by a servomotor.

[0022]

The invention according to claim 1 is intended to intermittently apply a metal web at a high speed so that the part of the metal web to be formed into a drawing cup is substantially exactly below the punch of the cupping machine. There is an effect that the squeezing cup can be manufactured by being fed. Therefore, the metal according to claim 2, wherein the biaxially oriented polyester film is heat-bonded to the metal strip, wherein the biaxially oriented degree of the central part of the part to be punched as a blank is higher than the biaxially oriented degree of the peripheral part. This has the advantage that it can be ensured that even in the case of manufacturing the drawing cup from the web, the central part is ensured to be the bottom of the drawing cup. The invention according to claim 2 is a seamless method in which the biaxially stretched polyester film is hardly peeled off from the web composed of the laminated body to which the biaxially stretched polyester film is thermally bonded, and the biaxially stretched polyester film at the bottom is hardly cracked. This produces an effect that a squeeze cup for forming a can can be manufactured at a high speed.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a metal web used for carrying out the present invention.

FIG. 2 is a plan view of an example of a blank punched from the metal web of FIG.

FIG. 3 is an illustrative side view of a cupping machine used in the practice of the present invention.

FIG. 4 is an explanatory plan view of the cupping machine of FIG. 3;

FIG. 5 is a longitudinal sectional view of the feeding roll device of the cupping machine of FIG. 3 as viewed from the front.

6 is a vertical sectional view of a main part of the feed roll device of FIG. 5, showing an operation when feeding a metal web.

FIG. 7 is an explanatory drawing showing an example of an image image obtained by an image sensor attached to the cupping machine of FIG. 3;

FIG. 8 is a longitudinal sectional view of an example of a drawing cup manufactured by the cupping machine of FIG. 3;

9 is a longitudinal sectional view of an example of a seamless can formed from the draw cup of FIG.

FIG. 10 is an enlarged vertical sectional view of a portion B of the seamless can of FIG. 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal web 2 Circular part (part to be punched) 2a Center 2b Central part 2d Peripheral part 3 Blank 4 Gauge mark 6 Metal plate (metal band) 7 Biaxially stretched polyester film 8 Cupping machine 8d Punch 9 Feed roll device 10 Rigidity Pressing roll 11 Drive roll 11y Elastic sleeve 17a Image sensor 17b Reference position 21 Squeeze cup

Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B65H 23/188 B65H 23/188 Z

Claims (2)

(57) [Claims] 1. A feed roll device comprising a rigid press roll and a drive roll having an outer peripheral portion formed of an elastic sleeve,
In a method of intermittently feeding a metal web into a cupping machine, punching a blank with a punch, forming by drawing, and forming a drawing cup, the rotation angle of a drive roll at the time of feeding is kept constant, and The elastic sleeve of the rigid press roll and the drive roll is based on the length of the gap between the gauge mark provided at the interval L equal to the predetermined feed length in the longitudinal direction and the reference position detected by the image sensor at the stop timing. , The feeding length of the metal web after the stop timing is adjusted, and the punch is aligned and positioned so that the axis of the punch is substantially positioned on the imaginary line in the width direction passing through the gauge mark. A method for producing a drawing cup, which is formed by molding. 2. A metal web comprising a laminate in which a biaxially stretched polyester film is thermally bonded to a metal strip, wherein the degree of biaxial orientation at the center of a portion to be punched as a blank is smaller than the degree of biaxial orientation at the peripheral edge. 2. The method according to claim 1, wherein a gauge mark is provided on an imaginary line in the width direction that is high and passes through the center of the portion to be punched.