JPH0116221B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a double-sealed can, and more specifically, a method for producing a double-sealed can in which the compressive axial load applied to the can body is extremely small when forming the double-sealed portion. Regarding.

In the conventional double seaming method, as shown in FIG.
After placing the curled part 4 (lid part or bottom part) and fitting the chuck 6 into the lid part 3 having the recessed panel part 5, the can body 1 is pushed up by a lifter (not shown) and the flange part 2 and curled. At the same time, as shown in FIG. 1b, the curled part 4 and the flange part 2 are pressed between the first seaming roll 7 and the chuck 6, so that the end 4a of the curled part is turned upward. Then, a preliminary seaming portion 8 is formed which enters the inside of the flange portion 2 facing downward, and then a second seaming roll 9 is used to seal the portion 4 against the curled portion end portion 4a.
This is done by forming a double seam 10 in which the part 2' (usually called the body hook) corresponding to the flange part 2' (usually called the cover hook) and the flange part 2 are in close contact with each other through a layer of sealing compound (not shown). It will be done. In addition, the double seaming part 10
The inner wall 11 rising from the periphery of the panel portion 5 of the end member 3 is usually called a chuck wall, and the outer wall 12 hanging down from the upper end of the inner wall 11 is usually called a seaming wall.

As described above, in the conventional double seaming method, the can body 1 is pushed up by the lifter and the flange portion 2 is
In order to deform the can body 1, a fairly large compressive axial load (for example, 120 to 150 kg) is applied to the can body 1. Therefore, when trying to apply the conventional double seaming method to the can body made of a material with low axial load strength, The can body buckles, making it impossible to obtain a satisfactory product. Therefore, the thickness of the can body can be made thinner than the specified value (for example, approximately 0.10 mm for tinned steel, approximately 0.13 mm for aluminum alloy) due to constraints from the axial load applied during double seaming. (Even if it is thinner than the above specified value, for example, in the case of a sealed can with an internal pressure higher than atmospheric pressure, problems such as deformation due to external pressure such as impact are unlikely to occur.) Therefore, the can body can be made thinner to reduce costs. It was difficult to achieve this goal.
For the same reason, it has been difficult to apply the conventional double seaming method to can bodies made of relatively thin plastics, paper materials, or laminates thereof (including laminates with metal foil). . Therefore, although the double-sealed part has the advantage of superior reliability in airtightness, the conventional double-sealed method cannot form the part of the can body mentioned above. The problem was that it was difficult.

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 manufacturing a double-sealed can in which a double-sealed portion is formed by an open end of a can body and an end member. An open end is formed in the curled part of an end member formed with a curled part consisting of an outer wall extending diagonally downwardly outward from the upper end, and a hook part extending diagonally upwardly inwardly from the lower end of the outer wall away from the inner wall and the outer wall. A flange portion extending obliquely downward and outward, formed in the above, is inserted into the curled portion by supporting the open end portion and pushing it up to form a preliminary seaming portion where the outer wall and the flange portion are in contact with each other. The present invention provides a method for manufacturing a double-sealed can, characterized in that a double-sealed portion is formed by applying a radially directed force to the pre-sealed portion.

Furthermore, the present invention provides a method for manufacturing a double-sealed can in which a double-sealed portion is formed by an open end of a can body and an end member, in which an inner wall extending upward from a peripheral edge of a panel portion;
In the curled portion of the end member, the curled portion is formed with an outer wall extending obliquely downward and outwardly from the upper end of the inner wall, and a hook portion extending obliquely upwardly inwardly from the lower end of the outer wall away from the inner wall and the outer wall, By inserting the straight cylindrical tip of the open end by supporting and pushing up the open end, and deforming the tip along the inner surface of the outer wall to form a flange portion that contacts the outer wall. , to provide a method for manufacturing a double-sealed can, characterized in that after forming a pre-sealed portion, a force directed inward in the radial direction is applied to the pre-sealed portion to form a double-sealed portion. It is.

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

As shown in FIGS. 6 and 10, the end member 20 (lid or bottom) to which the present invention is applied includes an inner wall 22 extending upward from the periphery of the panel portion 21, and an outer side diagonally downward from the upper end of the inner wall 22. an outer wall 23 extending to
and a hook portion 24 that extends obliquely upward and inward from the lower end of the outer wall 23, is spaced apart from the outer wall 23 and the inner wall 22, and is to become the cover hook 26 of the double seam portion 25 (see FIG. 9) to be formed. A curled portion 27 is formed. Such a curl portion 27 can be formed by a curler 28 as shown in FIG. 2, for example. In FIG. 2, 29 is an entrance side guide, and the end member blank 20' formed by a press or the like having the cross-sectional shape shown in FIG. 3 is moved along the entrance side guide 29 by a feeding mechanism (not shown). It is transported in the direction of arrow A. 30 is a forming roll, which has an approximately semi-elliptical cross section (see Figures 3 to 5).
A peripheral groove 31 is formed and rotated at a constant speed in the direction of arrow B by a drive mechanism (not shown). Reference numeral 32 denotes a semicircular arc-shaped forming die that is connected to the outer wall 29a of the entrance side guide 29 and extends along the outside of the forming roll 30, and has a forming groove 33 formed opposite to the peripheral groove 31. . Molding groove 33
The cross-sectional shape of is the third in the vicinity of the entrance of the forming die 32
As shown in FIG. As shown in FIG.
It has a shape that almost corresponds to the curled portion 20''a that is formed in the middle of the formation of the end member 7. Also, as the outer diameter of the end member becomes smaller as it approaches the exit side due to the formation of the curled portion 27, the outer diameter of the end member becomes smaller. forming groove 33
is configured to approach forming rolls 30. 34 is an exit side guide, and its outer wall 3
4a is connected to the forming die 32. The end member blank 20' sent from the entrance side guide 29 to the forming die 32 is rotated in the direction of arrow C by the forming roll 30, and is formed into a curled part 27 of a predetermined shape by the peripheral groove 31 and the forming groove 33. is formed and sent out to the next process through the exit side guide 34.

The material of the end member 20 is a metal plate such as a tin-plated steel plate, a stain-free steel plate, or an aluminum (alloy) plate (including those with a coating film, a printed film, etc. formed on the surface), or a metal foil (with a high seaming strength). In order to ensure that
Approximately 20μm for steel or iron-based foils
A laminated material of a plastic film or sheet and a plastic film or sheet is selected depending on the purpose of use.

Can body 4 in the examples of FIGS. 6, 7, and 8
A flange portion 41 extending obliquely downward and outward is formed at the open end portion 40a of 0. Such a flange portion 41 can be formed by applying an axial load to a relatively small can body 40, for example, by a spinning method as disclosed in Japanese Utility Model Publication No. 46-19409. Can body 40 shown in FIG.
is a seamless can body formed by drawing or drawing-ironing a metal plate.
metal plates, plastic sheets, paper materials (including those impregnated or coated with wax or plastic), or plastic sheets or films;
Two open ends formed by welding, soldering, or gluing (including heat fusion) opposite ends of a blank made of a laminate made of an appropriate combination of paper materials and metal foil to form a side joint. The can body may have a The present invention is particularly suitably applied to can bodies made of thin walls with low axial load strength or materials with poor rigidity.

Reference numeral 42 denotes an end member holder, which holds the panel portion 21 of the end member 20 by vacuum suction through a vacuum guide hole 43 that communicates with a vacuum device (not shown). Holder 42
is configured to be rotatable at the same speed as the lifter 44 that supports the can body 40 by a drive mechanism (not shown). The lifter 44 is further configured to be movable up and down by a drive mechanism (not shown). Reference numeral 45 is a spatula-shaped push-up tool whose tip 45a can be inserted into the recess 46 formed by the flange 41, and at a fixed position in the circumferential direction of the can body 40, the flange 41, it is configured to be able to move up and down together with the lifter 44.

As shown in FIG. 6, the end member 20 (lid in this case) is held in position by the holder 42, and is placed on the lifter 44 to hold the contents 47.
With the push-up tool 45 engaged with the lower surface of the flange portion 41 of the filled can body 40, the push-up tool 4
Increase with 5. Then, the flange part 41
The lower surface is supported and pushed up by the push-up tool 45 while rotationally slipping with the tip 45a of the push-up tool 45 (at this time, the flange portion 41 is connected to the inner wall 22).
and the hook part 24), as shown in FIG. 7, the flange part 41
is fitted into the curled portion 27 to form a preliminary seaming portion 48 in which the outer wall 23 and the flange portion 41 are in contact with each other, corresponding to the preliminary seaming portion 8 shown in FIG. 1B. At this time, the flange portion 41 is supported and pushed up by the pushing up tool 45, so that almost no axial load is applied to the can body 40. Next, according to the conventional method, a force directed inward in the radial direction is applied to the preliminary seaming portion 48 by a second seaming roll (see 9 in FIG. 1c) to form a double seam as shown in FIG. A double seamed can 49 having a seamed portion 25 formed therein is manufactured. The hook portion 24 and the flange portion 41 become the cover hook 26 and body hook 50 of the double-sealed portion 49, respectively.

FIG. 10 and FIG. 11 show a case where the open end 40a of the can body 40 does not have a flange part and the tip 40a' of the open end 40a has a straight cylindrical shape.
This figure shows an example of forming the preliminary seaming portion 48. The inner wall 22 of the end member 20 used rises vertically from the periphery of the panel portion 21, and has a straight cylindrical shape.
The outer diameter of the opening end and the inner diameter of the tip 40a' of the open end are determined to be approximately equal. In addition, the inner wall 22 and the hook portion 24
The gap therebetween may also be narrower than in the case of FIG. 6, that is, it may be slightly larger than the wall thickness of the tip 40a'. Furthermore, in order to ensure engagement with a screw-shaped rotary tool 51 to be described later, the inner wall 22 has a curled portion 27.
It extends slightly below the lower end 27a. The holder 42 and lifter 44 are configured to rotate at the same rotational speed, as in the case of FIG. 6.

Reference numeral 51 is a screw-shaped rotary tool whose axis is vertically supported by a support 52 and configured to be rotated by a drive mechanism (not shown) via a belt 53.

The tip 40a' is preferably a thermoplastic sheet or a laminate composed of thermoplastic sheets as the main layer, and the tip 40a' is heated to a temperature above its softening point (within a range where it does not melt) to form the material shown in FIG. As shown, it is inserted into the curled portion 27, and its tip is brought into contact with the inner surface of the curled portion 27. Next, the screw-shaped rotary tool 51 is pressed against the portion 40a'' of the open end 40a directly below the curled portion 27, and the portion 22a of the inner wall 22 in contact with the open end portion 40a'' is moved between the rotary tool 51 and the holder 42. The holder 42, lifter 44, and rotary tool 51 are rotated in the direction of the arrow while being pressed between them. Due to this rotation, a lifting force is applied to the opening end 40a by the screwing action of the rotary tool 51, so that the lifter 44 is raised at the same speed as the lifting speed. As the open end 40a rises, that is, the tip 40a' is pushed into the curled part 27, the heated and softened tip 40a'
As shown in FIG. 1, the pre-sealing portion 48 is formed on a flange portion 54 extending diagonally downward and outward along the inner surface of the outer wall 23 of the curl portion 27. After the preliminary seaming portion 48 is formed, the support body 52 is tilted as shown in FIG. 11, and the push-up by the rotary tool 51 is stopped. Next, the preliminary seaming part 48 applies a force directed inward in the radial direction by a second seaming roll (see 9 in FIG. 1c) to form the double seaming part 25 as shown in FIG. It is formed. Since the can body 40 is pushed up during the formation of the preliminary seaming portion 54 mainly by the rotary tool 51, almost no axial load is applied to the can body 40.

The present invention is not limited to the above-described embodiments, and for example, a pair of semi-annular magnets may be attached near the open end 40a (provided that the open end is made of a ferromagnetic material).
Alternatively, the preliminary seaming portion 48 can be simultaneously tightened along the entire circumference by holding the magnet or vacuum holding member by holding it with a vacuum holding member (not shown) and pushing up the magnet or the vacuum holding member without rotating the holding member 42 and the lifter 44. may be formed.

According to the present invention, the flange portion or the tip portion of the can body is supported and pushed up on the curled portion of the end member, which is formed in advance in a shape corresponding to the pre-sealed portion, so that the pre-sealed portion can be pre-sealed. Since a tightening section is formed, it has the effect that almost no axial load is applied to the can body during the formation of the preliminary tightening section. Therefore, it is possible to double-seal can bodies with thin walls or bodies with low rigidity, which was previously impossible, and this has the advantage of reducing material costs or expanding the range of material selection. .

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of the main part for explaining the conventional double seaming method, in which Fig. 1a shows the state before double seaming, and Fig. 1b shows the preliminary seaming section. Fig. 1c shows a state in which a double seam part is formed, and Fig. 2 shows an apparatus for forming a curled part of an end member to which the present invention is applied. A plan view of the example, Fig. 3 is a longitudinal sectional view taken along the - line in Fig. 2, Fig. 4 is a longitudinal sectional view taken along the - line in Fig. 2, and Fig. 5 is a longitudinal sectional view taken along the - line in Fig. 2. side view,
6 and 7 are longitudinal sectional views for explaining the first example of the manufacturing method of the present invention, in which FIG. 6 shows a state before the preliminary seaming part is formed, and FIG. Figure 8 is a plan view taken from the - line in Figure 6, and Figure 9 is a longitudinal cross-sectional view of an example of a double-sealed can manufactured by the method of the present invention. , FIG. 10, and FIG. 11 are longitudinal cross-sectional views for explaining the second example of the manufacturing method of the present invention, in which FIG. The figure is a drawing showing the state after the preliminary seaming part is formed. 20... End member, 21... Panel portion, 22...
Inner wall, 23... Outer wall, 24... Hook portion, 25...
...double seaming part, 27... curl part, 40... can body, 40a... open end, 40a'... tip part, 4
1...Flange part, 48...Preliminary seaming part, 49...
...Double-sealed can.

Claims (1)

[Scope of Claims] 1. A method for manufacturing a double-sealed can in which a double-sealed portion is formed by an open end of a can body and an end member, comprising: an inner wall extending upward from the periphery of the panel portion; An open end is formed in the curled part of the end member, which is formed with a curled part consisting of an outer wall extending downward and outward, and a hook part extending obliquely upward and inward from the lower end of the outer wall and away from the inner wall and the outer wall. A flange portion extending diagonally downward and outward is inserted into the curled portion by supporting the open end and pushing up to form a pre-sealed portion where the outer wall and the flange portion are in contact with each other. A method for manufacturing a double-sealed can, characterized in that a double-sealed portion is formed by applying a radially inward force to the tightened portion. 2. A method for manufacturing a double-sealed can in which a double-sealed portion is formed by the open end of the can body and the end member, including: an inner wall extending upward from the periphery of the panel portion; an outer wall extending obliquely downward and outward from the upper end of the inner wall; and insert the straight cylindrical tip of the open end into the curled part of the end member, which is formed with a curled part consisting of a hook part extending diagonally upward and inward away from the inner wall and the outer wall from the lower end of the outer wall. After forming a preliminary seaming part by supporting and pushing up the end part and deforming the tip part along the inner surface of the outer wall to form a flange part that contacts the outer wall, the preliminary seaming part is formed. A method for manufacturing a double-sealed can, characterized in that a double-sealed portion is formed by applying a radially inward force to the seamed portion.