JPH01167050A - Double seam can lid and manufacture thereof - Google Patents

Abstract

PURPOSE:To permit an accurate double seaming, if the leg length of a can lid is shortened, by providing a shoulder portion with a specific shoulder angle formed to chuck panel center and providing each of seaming panel radius portion, seaming panel portion and curl portion with its own radius of curvature. CONSTITUTION:By providing a shoulder portion 7 with the shoulder angle theta2 formed within the range of 10-15 deg. to a chuck panel center 8, a seaming panel radius portion 2 with a radius of curvature within the range of 1.7-2.0mm and a seaming panel portion 3 with a radius of curvature within the range of 4.5-5.3mm, the possibility of the end of a can flange portion hitting against the surface of a can lid 1 can be eliminated, even if the length of the lid leg is shortened. By providing a curl portion 4 with a radius of curvature within the range of 1.1-1.3mm and the end of the curl portion with a straight portion 5 having a length within the range of 0.1-0.4mm, the downward angle of the straight portion 5 thereof from the horizontal can be reduced to 0-25 deg. and the possibility of the end of the curl portion hitting against the can wall can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a can lid that is double-sealed to the opening of a can body, and a method for manufacturing the same.

(Prior Art) In order to avoid poor seaming, etc., in the seamed portion of the can lid of this type of double seamed can, various dimensions of the seamed portion as shown in FIG. Dimensions such as the winding height A1, the body hook portion B, the cover hook portion C1, and the overlap portion are set.

Therefore, in order to secure the dimensions of the seamed portion of the can lid, conventionally, the can lid 1 is first sealed by press working as shown in Figure 5. The radius of curvature R of the seaming panel radius portion 2 is set to 2.05 to 2.05. 2.15 mm, the radius of curvature Q of the seaming panel part 3 is 4.0 to 4.45 mm, the radius of curvature P of the curled part 4 is 0.5 to 1.0 mm, and the straight part 5 at the tip of the curled part
The length is set to 0.9 to 2 mm, and the angle on the side where the straight part 5 enters is set to 5 mm as shown in Figure 6.
The curled portion 4 is curled using a curling group having an angle of 18° to 25° on the side to be extruded after being curled, and the flange portion of the can body 6 as shown in FIG. 7 is obtained. The shape had a joint part continuous with 6a.

However, in recent years, in order to reduce the manufacturing cost of cans, the so-called lid leg length S of the can lid 1 shown in the fifth figure is shortened as shown in the eighth figure 81.
Attempts have been made to form a double seam portion which is smaller than the conventional seam portion shown in the fourth figure and has the same sealing performance as shown in the figure.

In the shape of this can lid 1, the radius of curvature R1 of the seaming panel radius portion 2 is 2.05 to 2.15 mm.

The radius of curvature Q1 of the seaming panel portion 3 is 4.0 to 4.4.
5 mm, and the radius of curvature P1 of the curled portion 4 is 0.5 to 1.0 m.
rrt is the same as the conventional one, but the length Ll of the straight end portion 5 of the curled portion 4 is 0. 6 to 1.0 mm, and by shortening the length of the seaming panel portion 3 compared to the conventional one, the length of the can circumference is shortened and the amount of material used is reduced.

When the curled portion 4 of the can lid 1 is curled using the curling group shown in FIG. 6 in a conventional manner, the can lid 1 is shaped as shown in FIG. 10.

In this shape, the shoulder angle e1 of the shoulder portion 7 with respect to the chuck panel center 8 is relatively large at 16° to 19°, and the tip straight portion 5 of the curled portion 4 shortens the seaming panel portion 3, so that the shoulder angle e1 with respect to the chuck panel center 8 becomes relatively large after curling. As shown in Fig. 11, it returns slightly due to the restoring force in the vicinity, forming a relatively large angle of 35° to 45° downward from the horizontal.

When double seaming is performed with the flange portion 6a of the can body 6 using the conventional can lid 1 shown in FIG. is made shorter than before, and the shoulder angle θ1 of the shoulder portion 7 is further reduced.
has become relatively large, the flange portion 6a of the can body 6
Conventionally, the can lid 1 is connected continuously to a predetermined length as shown in FIG. 7, but a gap a is formed as shown in FIG. 10, and the tip of the flange 6a of the can body 6 It hits the surface of can lid 1.

As a result, the tip of the flange portion 6a pierces the can lid 1 during double seaming, and the sealing rubber (not shown) coated on the surface of the can M1 is scraped and the seaming progresses. The flange portion 6a of No. 6 is subjected to resistance, and the portion that becomes the body hook portion B shown in FIG. 9 is difficult to be formed.
The length of this portion may not be sufficient, or the tip of the curled portion 4 may become bent at the portion where it hits the can lid 1 at the tip of the flange 6a.

Further, the length Ll of the straight portion 5 at the tip of the curled portion 4 is relatively long, and the downward angle of the straight portion 5 at the tip of the curled portion 4 with respect to the horizontal is as large as 35° to 45°. The tip of the can body 5 abuts against the side wall of the can body and is tightened while receiving resistance, causing wrinkles to occur in the portion that will become the cover footer portion C shown in FIG. 9, and scratches and cracks to the can body 6.

For this reason, the portion that will become the cover footer portion C will not be formed, and the length of this portion will not be sufficient, and furthermore, it will be difficult to obtain a sufficient length of the portion that will become the overlap portion.

Therefore, according to such a method, the lengths of various parts of the double-sealed portion, such as the above-mentioned B and C, cannot be obtained as specified, which tends to cause leakage of the contents, and also, Damage to the side wall of the fastening section.

(Problems to be Solved) In order to solve this problem, the present invention provides a method that allows good and reliable double seaming with the conventional can body flange even if the length of the lid leg of the can lid is shortened compared to the conventional one. It is an object of the present invention to provide a can lid and a manufacturing method thereof, which can form a double-sealed portion that is smaller in shape than conventional can lids.

Means for Solving Problem C) In order to achieve this object, the can lid according to the first invention has a shoulder angle of 10' to 10' with respect to the center of the chuck panel.
Shoulder part in the range of 15° and radius of curvature from 1.7 to 2
．． A seaming panel radius portion having a radius of curvature of 0 mm, a seaming panel portion having a radius of curvature of 4.5 to 5.3 mm, and a curl portion having a radius of curvature of 1.1 to 1.3 mm, The straight part at the tip of the curl part forms an angle in the range of 0° to 25° downward with respect to the horizontal, and the length thereof is 0.1
It is characterized by being in the range of ~0.4 mm.

Further, in the method for manufacturing a can lid according to the second aspect of the present invention, the seaming panel radius portion is formed with a radius of curvature in the range of 1.7 to 2.0 mm, and the radius of curvature of the seaming panel portion is set to 4.5 mm.
- 5.3 mm, and the distance of the press die ring center in the seamin panel part from the chuck panel center is 4.6 to 5.0 mm, and the radius of curvature of the curled part is 1.1 to 1.3 mm. The length of the straight part at the tip of the curled part is 0.1 to 0.4 m.
a pressing process to form the curled portion in the range of m, and then curling to form the curled part at an angle of 13' to 17' on each side from the center line, and a total angle of 26 to 34'. The method is characterized by comprising a curling process in which curling is performed using groups.

(Function) In the first aspect of the means, the shoulder portion forms a shoulder angle in a range of 10° to 15° with respect to the center of the chuck panel, and the seaming panel radius portion has a shoulder angle of 1.7 to 2.0 mm. Furthermore, the seaming panel portion has a radius of curvature in the range of 4.5 to 5.3 mm, so that the can lid and can body can have a shorter length of the lid than before. During double seaming, a continuous joint portion of a predetermined length is formed between the can lid and the can body flange portion, and the tip of the can body flange portion abuts against the surface of the can lid. Eliminate. Furthermore, by setting the radius of curvature of the curled part in the range of 1.1 to 1.3 mm and the length of the straight part at the tip of the curled part to be in the range of 0.1 to 0.4 mm, the straight line of the tip of the curled part is The downward angle of the curled portion with respect to the horizontal can be reduced to 0° to 25°, which is smaller than the conventional method, and the tip of the curled portion can be prevented from abutting against the side wall of the can body.

Further, in the second invention, the press working step reduces the radius of curvature of the seaming panel radius portion of the can lid, increases the radius of curvature of the seaming panel portion, and presses the press die as described above. The distance between the ring center and the chuck springcle center is also increased, so that it is possible to form a can lid shape that forms a suitable continuous joint with the can body flange part during double seaming with the can body. In addition, in the curling process, the penetration angle of the curling group is increased to 13° to F'' compared to the conventional method,
In addition, by reducing the angle of the extruded side after curling to 13° to 17'', and curling with a curling group with a total shape of 26° to 34'', the length of the curling process was reduced compared to the conventional method. The curled part, which has a straight tip and a large radius of curvature, can enter the group without bending, and furthermore, the seaming panel part of the can lid can be connected to the flange part of the can body during double seaming. It is possible to form a can lid shape that is suitably joined, and to make it possible to reduce the downward angle of the straight portion of the tip of the curled portion with respect to the horizontal to 0° to 25° compared to the conventional art.

(Example) Hereinafter, one embodiment of the method according to the present invention will be described in detail.

An aluminum can lid material is pressed so that the shoulder angle θ2 is 13° as shown in the first diagram, the radius of curvature R2 of the seaming panel radius portion 2 is 1.8 mm, and the seaming panel portion 3 is
The radius of curvature Q2 is 4.8 mm, and the press die ring center 9 in the seaming panel section 3 is located at a distance of 4.7 mm from the chuck panel center 8.
A can lid 1 was molded having a radius of curvature P2 of 1.2 mm and a length L2 of the straight portion 5 at the tip of the curled portion 4 of 0.3 mm.

Thereafter, the curled portion 4 was curled using curling groups forming 14° angles on both sides from the horizontal center line and having a total length of 28″ as shown in Figure 2a.

As a result, the radius of curvature P2 of the curled portion 4 is larger than before, the press die ring center 9 is closer to the curled portion 4 than before, and the straight end straight line 5 of the curled portion 4 is shorter than before. Therefore, the curl part 4 can be formed along the curling group as shown in Figure 2b,
Furthermore, a can lid 1 having a shape as shown in FIG. 3 was formed in which the straight portion 5 at the tip of the curled portion 4 forms an angle of about 20° downward from the horizontal, which is smaller than the conventional one.

Further, in FIG. 3, reference numeral 6a indicates a flange portion 6a of the aluminum can body 6 which is rolled together with the can lid 1. As shown in FIG.

Next, the results of studies regarding the length and angle of each part of the can lid 1 when the can lid 1 and the flange portion 6a of the can body 6 are double-sealed will be described in detail.

First, if the shoulder angle e2 shown in the third diagram is set to 10@ or less, the diameter of the chuck wall portion of the can lid 1 becomes too small relative to the inner diameter of the can body 6, and the fit between the can body 6 and the can lid 1 becomes poor. As a result, it was found that wrinkles and stepped portions were formed at each joint.

Furthermore, when the shoulder angle θ2 is set to 15@ or more, a gap is generated between the can lid 1 and the flange portion 6a of the can body 6, and as pointed out as the problem with the conventional method, the flange portion 6a When the tip of the can hits the surface of the can lid 1,
The seaming rubber applied to the surface is seamed and then seamed, and the body hook portion B at the double seamed portion is tightened.
It becomes impossible to obtain a sufficient length.

Further, if the radius of curvature R2 of the seaming panel radius portion 2 is set to 1.7 mm or less, the flange portion 6 of the can 1ri[6]
a does not enter the inner surface of the curled part 4 of the can lid 1, and further 2,0
mm or more, a gap will be created between the can lid 1 and the flange portion 6a and the tip of the flange portion 6a will abut against the surface of the can lid 1 as described above. The radius of curvature R2 is 1. 7-2.0m
Make it m.

Further, as a result of examining the radius of curvature Q2 of the seaming panel portion 3, it was found that if the radius of curvature Q2 is set in the range of 4.5 to 5.3, the shoulder angle θ2 and the radius of curvature R2 of the seaming panel radius portion 2 are It has been found that in the case of a preferable range of , the flange portion 6a of the can M1 and the can body 6 form a continuous joint suitable for double seaming as shown in the third figure.

In addition, the length L2 of the straight part 5 at the tip of the curled part 4 is 0.1 m.
m or less, the straight part 5 will be cut with a tool during press working.
Can lid 1
The product dimensions may vary, or the portion 5 may be deformed or wrinkled due to insufficient clamping by tools during processing.

Furthermore, the length L2 of the straight portion 5 at the tip of the curled portion 4 is set to 0.
If it is 4 mm or more, the tip of the straight portion 5 will come into contact with the side wall of the can body 6 during seaming, causing problems such as damaging the side wall of the can body 6 described above.

Therefore, it is preferable to set the length L2 in a range of 0.1 to 0.4 mm.

Furthermore, it has been found that if the straight portion 5 at the tip of the curled portion 4 is at an angle of 25° or more with respect to the horizontal, there is a risk that the straight portion 5 will hit the side wall of the can body 2 as described above due to the difference in double seaming.

In addition, the portion where the straight portion 5 is above the horizontal is placed on the can body 2.
Since it becomes difficult to double seam along the side wall of the Q2.R2, Q2. .L2
In order to form the curling group within a predetermined value range, and then set the angle within the range of 0° to 25°, the angle on the intrusion side of the curling group should be 13° to 17°, and the angle on the side pushed out by the curl portion should be 13° to 25°. The range is between 17° and 26° overall.
It has been found that a range of 34° is suitable.

As mentioned above, θ2. As a result of setting R2, Q2, and L2, it was found that the radius of curvature P2 of the curled portion 4 should be set within a range of 1.1 to 1.3 mm.

Also, in order to set it in this way, as a result of experiments, the die ring center 9 must be set 4.6 to 4.6 mm from the chuck panel center 8.
5. It was found that it is sufficient to set the value within the range of Qmm.

That is, if the distance of the die ring center 9 from the chuck panel center 8 is set to 4.6 mm or less, the radius of curvature R2 of the seaming panel radius portion 2 becomes smaller than the set range, and the can lid A gap is created between the can body 1 and the flange portion 6a of the can body 6 during seaming.

Further, if the distance is set to 5.9 mm or more, the value of R2 becomes larger than the above setting range, and furthermore, it is difficult to set the length 2 of the straight part 5 at the tip of the curled part 4 to the above setting range. It becomes difficult.

Therefore, if each of the above-mentioned parts of the can lid l shown in the third figure formed in the above embodiment is set within the setting range determined from the above study results, the shape is smaller than the conventional one as shown in the ninth figure. It is possible to form a can lid 1 that can be double-sealed well and reliably with the flange portion 6a of the can body 6.

(Effect) As a result, according to the first invention, when the can lid and the can body are double-sealed with the length of the lid leg shortened compared to the conventional case, there is a gap between the can lid and the can body flange portion. It is possible to form a joint portion of a predetermined length on the can body flange, prevent the tip of the can body flange portion from abutting against the surface of the can lid, and further reduce the downward angle of the straight portion of the tip of the curled portion with respect to the horizontal. This can be reduced compared to the conventional method, and it is possible to prevent the tip of the curled portion from abutting against the side wall of the can body.

According to the second invention, the press working step reduces the radius of curvature of the seaming panel radius portion of the can lid, increases the radius of curvature of the seaming panel portion, and press-dies. By increasing the distance to the center chuck panel center, it is possible to form a can lid shape that forms a suitable joint with the can body flange when double seaming with the can body. By curling with a curling group that has a larger intrusion angle than the conventional one and a small angle on the side that is extruded after curling, it has a direct tip part that is shorter than the conventional one by the press working process, and has a curvature. A can in which a curled part formed with a large radius can be inserted into the group without bending, and the seaming panel part of the can lid is suitably joined to the flange part of the can body during double seaming. It is possible to form a lid shape, and the downward angle of the straight part of the tip of the curled part with respect to the horizontal can be made smaller than in the past, and the tip of the curled part can be prevented from hitting the side wall of the can body during double seaming. It can be resolved.

Therefore, according to the present invention, even if the length of the lid leg of the can lid is shortened compared to the conventional method, good and reliable double seaming with the can body flange can be performed, and furthermore, the seaming can be performed with a smaller shape than the conventional method. It is possible to provide a can lid and a method for manufacturing the same.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a partial sectional view showing the shape of an embodiment of the can lid according to the present invention, and FIGS. A partial cross-sectional view of the curling group, Fig. 3 is a partial cross-sectional view for explaining the joining state of the can lid and can body shown in Fig. 1 during seaming, and Fig. 4 is a portion of the conventional double seaming part. 5 to 8 are partial cross-sectional views for explaining the conventional product, and FIG. 9 is a partial cross-sectional view for explaining the conventional and the double seaming portion aimed at in the present invention.
FIGS. 10 and 11 are partial cross-sectional views for explaining the conventional product.・Straight line part 7 at the tip of the curl part...Shoulder part 8...Chuck panel center 9...Press die ring center θ2...Shoulder angle

Claims (1)

[Claims] 1. The shoulder angle is 1 with respect to the center of the chuck panel.
The shoulder part ranges from 0° to 15° and the radius of curvature is 1.
A seaming panel radius portion having a radius of curvature of 7 to 2.0 mm, a seaming panel portion having a radius of curvature of 4.5 to 5.3 mm, and a curl portion having a radius of curvature of 1.1 to 1.3 mm. The straight part at the tip of the curled part forms an angle in the range of 0 to 25 degrees downward with respect to the horizontal, and the length is 0.
．． A can lid 2 for double seaming characterized by having a radius of curvature in the range of 1 to 0.4 mm, and a radius of curvature of the seaming panel radius of 1.7 to 2.
．． The seaming panel portion is formed with a radius of curvature of 4.5 to 5.3 mm, and the press die ring center of the seaming panel portion is formed within a radius of 4.6 to 5.0 mm from the chuck panel center. The radius of curvature of the curled part is formed within the range of 1.1 to 1.3 mm, and the length of the straight part at the tip of the curled part is set to 0.1 mm.
A press working step to form the curled part in the range of ~0.4mm, and then a curling process of 13° to 17° on both sides from the center line.
A method for manufacturing a can lid for double seaming, comprising a curling process of curling using a curling group forming an angle in the range of 26° to 34° as a whole.