JPS5944258B2 - Tension piece for easy-open container lid and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pull piece for an easy-to-open container lid and a method for manufacturing the same.

Conventionally, as shown in Fig. 5, this kind of container lid is made by fitting the mounting hole E provided at the front end of the tension piece 2 into the rivet in the score line opening formed on the can lid plate A, and then caulking and connecting the tension piece. A container lid is known in which the container lid is opened by attaching a pull piece 2 and grasping the rear end of the pull piece 2 and lifting it.

In such a case, as shown in Figure 6, it is also possible to provide a folded part on the upper surface of the inner peripheral edge of the mounting hole of the tension piece to strengthen the mounting hole. It is being said. However, simply providing the folded part that is folded outward is not sufficient to reinforce the reinforcement, and when the tension piece 2 is lifted to open the folded part, there is a tendency for the folded part to expand outward, and the tension piece 2 tends to expand outward. When opening due to correct gripping or when the degree of caulking is weak, etc., a portion of the tension piece located on line A-A shown in Fig. 5 tends to bend and deform, causing the mounting hole to expand outward. However, there is a disadvantage that the tension piece 2 tends to fall off the rivet. Moreover, in this type of device, after drilling the mounting hole E, the peripheral edge thereof is bent upward or downward to form a folded portion. Therefore, when the bending process is performed, stress is concentrated on the peripheral edge of the mounting hole E, and cracks and tears are likely to occur in this area. Further, for this reason, the folded part cannot be folded back sufficiently, and a gap tends to be formed between the folded part and the folded part, and the presence of this gap makes the height H of the mounting hole unstable. After attaching such a tension piece 2 to the rivet in the stake panner process, when the rivet head is crushed and caulked together, it is difficult to form a normal rivet head.
Sometimes, as shown in Figure T, the rivet's round edge is pressed unnecessarily, resulting in inconveniences such as tearing or cracking.

Additionally, the outer edge of the rivet head is subject to severe machining, which is a particular problem when tinplate or stain-free steel lids are used, and requires corrective painting, causing bulges in the way the rivet head fits. Since the correction paint is hard to adhere to the periphery of the lower part, uncorrected painted areas are likely to occur, and these areas are disadvantageously rusted and corroded, resulting in defective products.

The first aspect of the present invention solves such conventional disadvantages, and the structure around the periphery of the mounting hole is strong, so there is no fear that the mounting hole will come loose from the rivet during the opening operation, and when it is mounted by caulking to the rivet. An object of the present invention is to provide a tension piece for an easy-to-open container lid, which has a structure that provides the periphery of a mounting hole with a function of suppressing excessive deformation of the rivet head, and facilitates correction painting of the rivet head. Then, fit the mounting hole provided at the front end of the tension piece into the rivet formed on the can lid plate within the score line, then caulk and connect to attach the tension piece, and grasp the rear end of the tension piece. In a container lid that is opened by lifting, the tension piece (the tension piece) is folded back in a momme direction on the upper surface of the inner periphery of the provided mounting hole to form a two-stage folded part that is further folded back inward, and an upper folded part. The diameter of the inner peripheral edge of the rivet is larger than the diameter of the rivet head.

The second aspect of the present invention aims to provide a manufacturing method that facilitates the production of the tension piece of the easy-to-open container lid of the first aspect. In a method for manufacturing a tension piece for a container lid, the method comprises: fitting a mounting hole provided at the front end of the tension piece, attaching the tension piece by caulking, and gripping and lifting the rear end of the tension piece to open the tension piece;
After forming a bulging part that bulges upward C at the front end of the tension piece by drawing, this is crushed in the vertical direction and the peripheral edge of the bulging part is folded maleward and further inward. forming a folded part, and then cutting off the flat top of the bulging part with a cutting blade to form a mounting hole having a diameter of the upper inner peripheral edge of the folded part larger than the missing diameter of the rivet head. It is characterized by 1 to 3 show easy-to-open container lids, in which 1 is a can lid plate, 2 is a score line formed on the can lid plate 1, and 3 is a line 1 on the can lid plate 1. The front end 3 of the tension piece 3 is shown attached to a rivet 4 provided within the score line 2.
After fitting the mounting hole 5 provided in a, the rivet 4 is pressed and connected by pressing and attaching. Up until now, there has been no particular difference from conventional easy-to-open container lids.

In such an easy-to-open container lid, the present invention has two folded portions 6 and 7 formed by folding the tension piece 3 outward and then folding it back inward on the upper surface of the inner peripheral edge of the mounting hole 5 provided in the tension piece 3. , and after fitting the tension piece 3 to the rivet 4 through its attachment hole 5, when the rivet 4 is crushed and caulked together, the inner circumferential edge Ra of the upper folded portion 7 and the circumferential edge 4a of the rivet 4 are A gap t was formed between them. In this case, it is preferable that the inner circumferential surface of the folded portion molecule has a tapered shape that widens toward the ground. In this case, the periphery of the folded part 6 that is folded inward can be reinforced by the inward folded part 7, and this makes it difficult for the receiving hole to be distorted when opening, thereby preventing the tension piece from becoming distorted. Difficulty in coming off the rivet 4 can be significantly reduced, and since a gap t is formed between the inner circumferential edge 7a of the upper folded part molecule and the circumferential edge 4a of the rivet 4, the paint can be applied in the gap when performing correction painting. This promotes the adhesion of the paint to the lower side of the periphery of the rivet 4, where paint is particularly difficult to adhere to, and a protective film can then be reliably formed on that part in the drying process using an oven. Next, a method of manufacturing the mounting hole 5 of the tension piece 3 will be explained.

First, the tensile piece material or the coiled tensile piece material M is used as the fourth material.
A gentle bulge X is squeezed into the material M by the upward motion of the bubble punch c which is held between the upper and lower dies A and b provided in the valve process shown in Figure A and inserted into the lower die b, and then The bubble-processed material M is fed between the upper and lower dies D and e in the button process shown in FIG. Draw and form into a long and thin shape. When the bulging portion X is formed by the two-stage drawing process in this way, it is possible to prevent the occurrence of distortion due to rapid deformation. Next, proceed to the forming process shown in FIG. 4C. Then, the bulging part , the folded portion 6 which is cut back in a notch and the folded portion 7 which is folded back inward are formed on the annular peripheral edge.

When the bulging portion X is press-molded in this manner, the portions to be press-molded are in a continuous state. That is, there is no edge portion where strain is concentrated, and thereby the folded portion 6 can be compressed to the top surface of the lid 1, and the folded portion 7 can be pressed to the top surface of the folded portion 6. Furthermore, by making the top portion sufficiently thin and flat, the folded portion molecules can be reinforced by movement of the material in the portion, which is advantageous. Next, this is sent between a pair of upper and lower dies K and m in the scoring process shown in FIG. Score processing is performed between a score die p equipped with one blade 0 and a support pin q.

Next, this is sent between the upper and lower dies R and s in the knockout process shown in FIG. 4E, and a part of the score is pushed up and removed by the upward movement of the knockout pin t provided on the lower die s.

The tension piece 3 thus obtained is shown in FIG.
It is supplied between the upper and lower dies U and V in the staking process shown in .

The rivet 4 is compressed and caulked between the rivet 4 and the anvil x by the upward movement of the stake punch W fitted into the lower die v.

At this time, the folded part 6 provided on the tension piece 3 is folded back so that the upper surface of the tension piece 3 and the folded part molecule are in close contact with the upper surface of the folded part 6, and its height position is fixed, so that the die U , v are accurately determined, and thereby the rivet 4 can be crushed by a predetermined amount, and the head of the rivet 4 is not strained, and moreover, a reliable caulking connection can be achieved. . As described above, as in the first invention, the two-stage folded portion 6, r is formed on the upper surface of the inner circumferential edge of the mounting hole 5 provided in the tension piece 3 by folding it back in the opposite direction and further folding it inward. The outer periphery of the folded part 6, which is folded back in the momme direction where the force is most likely to be applied when opening, can be reinforced by the folded part 7, thereby causing inconveniences such as the mounting hole 5 becoming distorted and falling out of the rivet when opening. Furthermore, since the diameter of the inner circumferential edge is made larger than the male diameter of the rivet head, when the rivet is caulked and connected, correction paint can be applied to the gap formed between the inner circumferential edge and the circumferential edge of the rivet. This makes it easier to paint the lower side of the rivet head, which is difficult to apply correction paint to. According to the second invention, after forming a bulge by drawing, the bulge is pressed vertically. By crushing and forming the two-stage folded portion on the periphery of the bulge, concentration of distortion can be avoided as much as possible during the molding, and then the flat top of the bulge is cut off to form the mounting hole. Since it is formed into a shape, it is easy to manufacture, and since there is little residual strain, it is possible to manufacture a tension piece with a strong inner circumferential edge of the mounting hole.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an example of the implementation of the present invention, FIG. 2 is a sectional view taken along the line 2, FIG. 3 is an enlarged view of the main parts, and FIG. FIG. 5 is a plan view showing the conventional example, FIG. 6 is a cross-sectional view thereof, and FIG. 1...Can lid plate, 2...Score line, 3
...Tension piece, 4...Rivet, 5...
...Mounting hole, 6,1...Folded part, 4a.
...peripheral edge, Ra...inner peripheral edge, t...
...Gap, X...Bulge, Y...Flat top.

Claims (1)

[Scope of Claims] 1. After fitting the rivet in the score line formed on the can lid plate into the mounting hole provided at the front end of the tension piece, the tension piece is attached by caulking, and the tension piece is attached to the back of the tension piece. In a container lid that is opened by gripping and lifting the end, a two-stage folded part is formed on the upper surface of the inner peripheral edge of the mounting hole provided in the tension piece, which is folded outward and then folded back inward. A tension piece for an easy-to-open container lid, characterized in that the diameter of the inner peripheral edge of the upper folded portion is larger than the diameter of the rivet head. 2. After fitting the mounting hole provided at the front end of the tension piece into the rivet in the score line formed on the can lid plate, attach the tension piece by caulking, grasp the rear end of the tension piece and lift it up. In a method of manufacturing a tension piece for a container lid that is opened by pressing, a bulge that bulges upward is formed at the front end of the tension piece by drawing, and then the bulge is crushed in a vertical direction to form the bulge. A two-stage folded part is formed by folding the circumferential edge of the folded part outward and then folded inward.Then, the flat top of the bulging part is cut off with a cutting blade, and the diameter of the inner circumferential edge above the folded part is set with a rivet. A method for producing a tension piece for an easy-to-open container lid, the method comprising forming a mounting hole having a diameter larger than the outer diameter of the head.