JPS5835029A - Forming method for double curled part - Google Patents

Abstract

PURPOSE:To form a double curled part nearly without applying an axial load to a can drum, by inserting the opening end part of the can drum between an internal and an external wall formed at the circumferential edge part of an end member, and forming it into a horizontal flange and then bending it at 90 deg.. CONSTITUTION:An interal wall 22 raised vertically from the panel part 21 of an end member 27 and an external wall 24 flexing and drooping from the upper end of the internal wall 22 are formed previously by press work, and the part 26a of the opening end part 26 of a can drum 25 is inserted into the gap between the internal wall 22 and external wall 24. Then, spinning work is carried out by a spinning roll 30 and a backup roll 32 to form the flange 28 which consists of the opening end part 26, internal wall 22 and external wall 24 and extends horizontally. Then, a chuck 44 is fitted in the end member 27 and an outer roll 47 is put closer to the opening end 26; and an upper curvature part 46a is used firstly and then a recessed part 46 is used secondary to press the flange 28, which is bent at 90 deg. to form a double curled part 45.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a double seam portion, and more particularly to a method for forming a double seam portion in which the axial load applied to the can body during formation is extremely small.

In the conventional double seaming method, as shown in FIG. After placing the curled part 4 of the can body 1 (the lower part or the bottom part) and fitting the chuck 6 into the lid part 3 having the recessed mother tongue part 5, while supporting the lower part of the can body 1 with a lifter (not shown), As shown in Figure (b), the curled part 4 and the flange part 2 are pressed between the first winding tightener, the lure, and the chuck 6, so that the end 4a of the curled part faces upward, and the flange faces downward. A preliminary seaming portion 8 is formed by entering the inside of the portion 2, and then a portion 4a' (corresponding to the curled portion end portion 4a) is formed by a second seaming whirl 9.
This is done by forming a cover footer (usually called a cover footer). Note that in the double-sealed portion IO, a rising portion 11Fi from the circumference of the groove or flannel portion 5 of the end member 3 is usually called a chuck wall. As described above, in the conventional double seaming method, especially in the process of forming the preliminary seaming part 8, the axial component force applied to the flange part 2 is supported to prevent the flange part 2 from escaping and In order to ensure the length of dead hook 2', a fairly large axial load (for example, 120 to 20
0 kfl) must be added to the can body 1 by a lifter, and therefore, when trying to apply the conventional double seaming method to a can body made of a material with low axial load resistance,
The can body buckles, making it impossible to obtain a satisfactory product. Therefore, the thickness of the can body is set to a predetermined value (for example, approximately 0.10 m for tin-plated steel, approximately 0.1 m for aluminum alloy) due to constraints from the axial load applied during double seaming.
3) It is not possible to make the can body thinner (even if it is thinner than the specified value above, problems such as deformation will not occur if the internal pressure is higher than atmospheric pressure, for example, in a sealed can), so the thickness of the can body should be made thinner. Therefore, it was difficult to reduce costs. For the same reason, it was difficult to apply the conventional double seaming method to can bodies made of relatively thin plastics, paper, or laminates thereof (including laminates with metal foil). .

Therefore, although the double-sealed part has the advantage of superior reliability in airtightness, it has the above-mentioned problems.
However, there was a problem in that it was difficult to form the can body using the conventional double seaming method.

The present invention aims to solve the problems of the prior art described above.

In order to achieve the above object, the present invention provides a method for forming a double-sealed part by an open end of a can body and an end member, in which an inner wall vertically rises from the tunnel part and a bent part from the upper end of the inner wall. an outer wall having a height equal to the length of the cover hook of the double-sealed part that hangs down through the end member, and a gap between the inner wall and the outer wall is approximately equal to the wall thickness of the open end; , a flange is formed by a spinning process into which the open end is inserted and extends horizontally by the open end and the end member located above the part corresponding to the chuck wall of the double seam part; The flange is pressed by the concave part of the outer roll having a concave part of the glofil corresponding to the outer protrusion of the double seam part, and the flan is bent 90 degrees to bring the outer wall into contact with the chuck wall. The present invention provides a method for forming a double-sealed portion, which is characterized in that the double-sealed portion is brought into close contact with the outer surface of an open end portion.

The present invention will be described below with reference to the drawings.

First, as shown in FIGS. 2 and 3, there is a tunnel portion 21, an inner wall 22 vertically rising from the tunnel portion 21, and a double winding that is to be formed by hanging down from the upper end of the inner wall 22 through a bent portion 23. It has an outer wall 24 with a height equal to the length of the cover hook (see 49 in FIG. 5(b)) of the closing part, and the outer diameter of the inner wall 22 is approximately equal to the inner diameter of the open end 26 of the can body 25. The gap between the inner wall 22 and the outer wall 24 is approximately equal to the thickness of the open end 26 of the end member 27 (the lid and bottom in the case of a 3-piece can, the lid in the case of a 2-piece can) by the pressing method. Manufactured by etc. The material of the end member 27 is a sheet based on steel such as a tin-plated steel plate or tin-free steel, or aluminum (
Metal plates such as alloy) plates (including those with coatings, printed films, etc. formed on the surface), or metal foils (approximately 20 μm or more in the case of steel or iron-based foils to ensure seaming strength) (in the case of aluminum foil, the thickness is desirably about 50 μm or more) and a glass film or sheet are selected depending on the purpose of use. can body 2
5 are metal plates, glass sheets, paper materials (impregnated or coated with wax or plastics, etc.),
Alternatively, it may be formed from a laminate made of a suitable combination of plastic sheets or films, paper materials, and metal foils.

As will be described later, in order to ensure the airtightness of the double-sealed part, after the open end 26 is fitted into the end member 27, or
When performing heat fusion after forming the heavy seam part, the can body 25
At least the inner layer and/or outer layer (not shown) of the open end 26 and/or the inner layer and/or outer layer (not shown) of the end member 27 are made of a heat-fusible film (for example, acid-modified or lyolefin resin). ). Note that instead of the heat-fusible film described above, a hot-melt adhesive may be applied to the surface.

Next, as shown in FIG. 2, the open end 26 of the can body is fitted into the gap between the inner wall 22 and outer wall 24 of the end member 27. After fitting, the open end 26, inner wall 22, and outer wall 24 are heat-sealed as necessary. Alternatively, if necessary, a hot melt adhesive may be applied in advance to the open end 26 or within the gap before thermal bonding is performed.

The opening end portion 26m located above the portion of the chuck wall 48 (see FIG. 5) of the double-sealed portion 45 to be formed thereafter, and the inner wall portion 22a1 of the end member outer wall 24 form the fourth A horizontally extending flange 28 as shown in Figure (b) is formed by spinning.

FIGS. 2 and 3 show an example of an apparatus for forming the flange 28 by the above-mentioned spinning process. 3
0 is a spinning roll, which is composed of a vertical cylindrical part 30a and a horizontal flange part 30b, and has a plurality of cylinders (four in the figure, but in actual work, as many as possible, preferably six or more) are rotatable. The shaft is mounted on a support plate 31. Each spinning roll is arranged such that the outer circumferential surface 303' of its vertical cylindrical portion 30a contacts the inner wall 22 of the end member. An outer circumferential surface 30a' of the vertical cylindrical portion 30a is connected to a horizontal lower surface 30b' of the horizontal flange portion 30b via a curved portion 30c. The height of the vertical cylindrical portion 30a is such that when the spinning roll 30 descends and the upper end of the inner wall 22 starts contacting the curved portion 30e as shown in FIG. It is desirable to be located approximately at the same level as or below the horizontal forming surface 32a (having approximately the same width as the flange 28) of the packer roll 32.When forming the flange,
The open end 26 and inner wall 22 of the can body are connected to the circumferential surface 32b of the backup roll 32 and the outer circumferential surface 308' of the vertical cylindrical portion 30a.
This is to reduce the axial load applied to the main part of the can body 25 during spinning processing. The width of the lower surface 30b' of the horizontal flange portion 30b is the width of the flange 2 to be formed.
It is determined to be approximately equal to the width of 8. The support plate 31 is the vertical axis 3
3, and the vertical shaft 33 is configured to be movable up and down within the fixed platen 34 by a drive mechanism (not shown).

The backup roll 32 is disposed outside the can body 25 opposite to the spinning roll 30, and is connected to the shaft 35.
It is rotatably mounted on the lower end of the shaft. The shaft 35 is pivotally mounted on a fixed plate 34 by a pin 36, and a cam roller 37, which is mounted on the upper end of the shaft 35, is constantly engaged with a cam 39 by a coil spring 38. cam 39
is fixed to the vertical shaft 33 and consists of an upper cylindrical portion 39a and a lower conical cone portion 39b. Therefore, when the vertical shaft 33 is rising, the cam roller 37 engages with the lower dome cone portion 39b and the backup roll 32Jd swings outward, so that the can body 25 and end member 27 before and after flange forming are Loading into and taking out of device A becomes possible. −
When the vertical shaft 33 is lowered and spinning is being performed, the cam roller 32 engages with the upper cylindrical portion 39a, and the backup roll 32 cooperates with the vertical cylindrical portion 30 of the spinning roll 30 to make contact. Press the opening end 26 portion and the inner wall 22 portion.

Reference numeral 40 denotes a rotary disk whose convex portion 40a has an outer diameter approximately equal to the inner diameter of the lower portion 25a of the can body 25. 41
are a pair of semicircular pressing tools whose inner diameter is approximately equal to the outer diameter of the lower part 25a, and which press the lower part 25a radially inward by a suitable suppressing mechanism 42 (for example, an electromagnetic solenoid),
Can body 25f: The zero rotation plate 40 fixed to the rotation plate 40 is rotated by a drive mechanism (not shown) via a shaft 43″f: When loading and removing the can body 25, the rotation plate 40 can be lowered. It is composed of

FIG. 2 shows a state immediately before the can body 25 with the end member 27 attached thereto is loaded into the apparatus A described above and subjected to spinning processing. From this state, rotate the rotary plate 4 degrees and rotate the can body 25.
When the shaft 33f is lowered while rotating, first, as shown in FIG. When the spinning roll 30, which begins to bend outward from the upper part of the outer wall 24, reaches its lowest point, the lower surface of the outer wall 24 becomes flat, as shown in FIG.
A flange 28 is formed which contacts the molding surface 32a of the rear f-roll 32 and extends horizontally. At this stage, flange 2
8 is pressed between the forming surface 32a and the lower surface 30b' of the horizontal flange portion 30b of the spinning roll, so that wrinkles are prevented from forming. Furthermore, as mentioned above, during the spinning process, the open end 26 and the inner wall 22 are pressed between the backup roll 32 and the vertical cylindrical part 30a of the spinning roll, so most of the axial load due to the spinning process, which is originally relatively small, is It is absorbed by the pressed open end portion, and is hardly applied to the main portion of the can body 25.

As mentioned above, fusing or gluing the open end 26 of the portion that will become the flange 28, the inner wall 22, and the outer wall 24 may cause these portions to separate during the flange formation depending on the material composition. In some cases, it is effective in preventing this separation.

Next, the can body 25 with the end member 27 attached and the flange 28 formed as described above is removed from the apparatus A, and the fifth
As shown in Figure (a), a chuck 44 is fitted into the end member 27, the lower part of the can body 25 is supported by a lifter (not shown), and the can body 25 is rotated by the chuck 44.

An outer roll 47 having a profile recess 46 corresponding to the outer protrusion of the double-sealed portion 45 (see FIG. 5(b)) to be formed at the same time is brought close to the open end 26.

At this time, the outer roll 47 is positioned so that the upper curved part 46a of the recess 46 initially contacts the tip of the flange 28, so as the outer roll 47 approaches, the flange 28 is bent downward by 90 degrees while being pressed. As a result, a double-sealed portion 45 is formed in close contact with the outer surface of the open end portion 26 where the outer wall 24 contacts the chuck wall 48, as shown in FIG. 5(b). The outer wall 24 serves as a so-called cover flank 5o of the double-sealed portion 45, and the portion 26a of the open end 26 fitted into the gap between the inner wall 22 and the outer wall 24 serves as a so-called body hook 5o. During this process, the axial load hardly changes. After forming the double seam portion 45,
If necessary, by heating the waist (for example, high-frequency induction heating), the heat-fusible film layer present in the waist can be melted or softened to further ensure airtightness.

The present invention is not limited to the above embodiments, and for example, the can body 25 may be fixed during the spinning process, and the spinning roll 30 and the backup roll 32 may be revolved simultaneously. Also, instead of the backup roll 32, the sixth
A pair of semicircular pressing bodies 51a and 51bi whose inner diameter is approximately equal to the outer diameter of the open end 26 as shown in FIGS.
The forming surfaces 51a' and 51b' (corresponding to the forming surface 32a of the backup roll) are arranged so as to be at the same level as the forming surface 32& of the backup roll shown in FIG. Piston 53a connected to a drive mechanism (for example, an air cylinder) not shown
, 53b, and the suppressor 51a.

51b is brought into contact with the open end 26, and the suppressor 51a.

51b and the vertical circle m part o outer peripheral surface 3 of the spinning roll 30
The flange 28 may be formed by pressing the open end 26 and the inner wall 22 between 0a' and the forming surfaces 51a/51b'.

According to the present invention, no axial load is applied to the can body during the formation of the double seam portion, so the method of the present invention can also be applied to can bodies that are relatively thin or made of materials with low strength. This has the effect of reducing material costs and widening the range of choices for can body materials. Note that as shown in FIG. 2, the inner wall 22 and outer wall 2 of the end member 27
Although it is possible to join the end member 27 and the can body by inserting the open end 26 of the can body into the gap between 4 and heat-sealing or thermally bonding the end member 27, it is possible to join the can body to the end member 27 by inserting the open end 26 of the can body into the gap between the two. pinholes are likely to occur in the air, and these pinholes impair airtightness. By forming such a joint part into a double seam part by the method of the present invention, this pinhole can be made to disappear under pressure, so there is an advantage that airtightness can be ensured.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of the main part for explaining the conventional double seaming method, and Fig. 1 (,) is a drawing showing the state before double seaming, and Fig. 1 (b) is A drawing showing a state in which a preliminary seaming part is formed, FIG. 1(c) is a drawing showing a state in which a double seaming part is formed, and FIG. 2 is an example of an apparatus for forming a flantz by the method of the present invention. Fig. 3 is a plan view taken from the line ■-■ in Fig. 2, and Fig. 4(a) is an enlarged longitudinal cross-section of the main part showing the state in the middle of forming a flange by the method of the present invention. figure,
Fig. 4(b) is an enlarged vertical cross-sectional view of the main part showing the state in which the flange formation has been completed, and Fig. 5(,) is the state before the flange is bent in order to form the entire double seam part by the method of the present invention. FIG. 5(b) is an enlarged longitudinal sectional view of the main part showing a state in which a double seaming part is formed, and FIG. 6 shows an apparatus for forming a flange by the method of the present invention. FIG. 7 is a plan view corresponding to FIG. 3 of the example shown in FIG. 21...Panel part, 22...Inner wall, 23...Bending part,
24... Outer wall, 25... Can body, 26... Opening end,
27... End member, 28... Franz, 45... Double seam portion, 46... Recessed portion, 47... Outer roll,
48...chuck wall, 49...cover hook. Applicant Akira Kishimoto Agent Patent Attorney Yue Shuto Figure 1 (0) (b) (c) Figure 3! $4 Figure (a) (b) Figure 5 (a) (b) Go to 71

Claims (1)

[Claims] (1) In the method of forming a double-sealed part by the open end of the can body and the end member, there is an inner wall that rises vertically from the mother tongue part, and an inner wall that hangs down from the upper end of the inner wall through a bent part. 2
The capperf of the heavy seam part has an outer wall with a height equal to the length of the rope, and the gap between the inner wall and the outer wall is approximately equal to the wall thickness of the opening end. The opening end is inserted, and a flange extending horizontally is formed by the opening end and the end member located above the portion of the double seaming portion corresponding to the chuck wall, and the double seaming portion is formed by spinning. The open end portion of the outer roll having a concave portion of the grofill corresponding to the outer protrusion of the seaming portion presses the flange to bend the flange 90 degrees and bring the outer wall into contact with the chuck wall. A method for forming a double-sealed portion, characterized in that the double-sealed portion is brought into close contact with the outer surface of the double-sealed portion.