JPS6119056Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a can body having a soldered lap seam and a hook seam. Specifically, by improving the structure of the soldered lap joint part, the present invention relates to a can body having a soldered lap seam and a hook joint. The present invention relates to a can body which has a good protective coating of tin solder and correction paint, and which improves the corrosion of the can material at the lap joint and the adverse effect on the contents of the can when the can body is made.

Conventionally, can bodies having this type of soldering lap seam and hook seam (lock and wrap seam) have wrap seams 3, 3 on the upper and lower edges of the can body 2 as side seams of the can body 2, as shown in FIG. 6, for example. It was common to have a lock seam 4 between both lap seams 3, 3. As shown in FIG. 7, the can body blank of such a conventional can has seam lap portions 5, 5 having a generally rectangular or trapezoidal shape formed on the inner side of the lap seam 3 at the upper and lower ends of one side edge of the blank 1. , Correspondingly, seam wrap portions 6, 6 are formed on the upper and lower ends of the other side edge of the blank 1 to form the outer surface side of the lap seam 3.
and each seam lap part 5, 5, 6, 6
Bent edges 7, 7 for forming a lock seam 4 are formed between them. The conventional method of forming a can body 2 using such a blank 1 is to fold the bent edges 7, 7 of the blank 1 together to form a hook seam 4, and then wrap (overlap) the seam lap parts 5, 6 together. Thereafter, the lap joint 3 and the hook joint 4 of the can body 2 are placed in a solder bath and soldered. Similarly, even if a correction paint is applied to this part, the paint is difficult to apply and the coating correction becomes incomplete. The reason for this is thought to be various factors, but one reason is that when the blank 1 is punched and formed as shown in Figure 7, or when some external force is applied during the process of forming the can body, the joint lap portion 5 of the blank 1, 5 bending portions 5a, 5
A burr as shown in FIG. 8 is likely to occur in the area b, and the protruding portion of the burr is difficult to protect and coat with solder and correction paint.

For this reason, if a conventional can body 2 of this type is filled with contents and stored, corrosion of the can material will occur in the poorly coated area with solder and paint at the lap seam 3, which will affect the quality of the can. There was a drawback that the quality of the contents deteriorated.

As a result of studies to eliminate the drawbacks of conventional products, the present invention was developed by simply changing the shape of the outer periphery of the seam lap, which is the inner side of the lap seam, when forming a can body. It was completed after discovering that the protective coating with correction paint was sufficiently effective. The gist of the present invention is to connect the blank 1 to the can body 2 in a can body consisting of a lap joint 3 and a hook joint 4 to which the side seam of the can body 2 is soldered.
When forming the lap joint 3, the approximately rectangular or trapezoidal joint lap portion 5 on the inner surface side of the lap joint 3 is formed with a curved portion on the outer periphery, and the seam lap portion 5 on the outside surface side of the lap joint 3 is formed into a curved shape. It is formed by polymerizing the portion 6 and attaching it with solder 8.

More specifically, with reference to FIGS. 1 to 4 showing an embodiment of the present invention, when the can body 2 is formed as in the conventional product, a substantially rectangular or substantially trapezoidal shape is formed on the inner surface of the lap seam 3. Bent parts 5a, 5 of seam lap parts 5, 5
The lap seam 3 and hook seam 4 shown in Figure 3 were soldered using the blank 1 shown in Figure 1, which was formed by punching a can stock so that b (the part indicated by the imaginary line in Figure 2) had a smooth curved shape. Can body 2 was obtained.
When the inner surfaces of the lap joints 3, 3 of this can body 2 were observed, it was found that the solder 8 sufficiently protected the cut ends of the outer peripheral edges of the joint lap parts 5, 5 as shown in the fourth figure. Even after the correction coating was applied, the correction paint was applied with sufficient protective coating. Further, no burrs, which are difficult to correct, were generated at the cut ends of the outer peripheral edges of the inner seam lap portions 5,5.

FIG. 5 shows a seam lap portion in another embodiment of the present invention, in which the shape of the approximately rectangular or approximately trapezoidal outer periphery of the seam lap portions 5, 5 of the blank 1 is made into a smoother curved shape than in the previous embodiment. In other words, the outer peripheral edge is curved as a whole.

When this blank 1 was used to form a can body 2 having a lap seam 3 and a hook seam 4 in the same manner as in the previous example, the same results as in the previous example were obtained. In the illustrated and described embodiment, the side joint is constituted by the lap joints 3, 3 at the upper and lower ends of the can body 1 and the hook joint 4 between the lap joints 3, 3. The method is not limited to can bodies having such side seams, but can also be applied to can bodies in which the lap seam 3 is located in the center of the can body 2.

As is clear from the above description, when the blank 1 is formed into the can body 2, the seam lap portion 5, which is approximately rectangular or trapezoidal and forms the inner side of the lap seam 3, is formed into a curved shape at the bent portion of the outer periphery. The solder 8 is formed on the seam lap part 6 which forms the outer surface of the lap seam 3, and polymerizes to form a solder 8.
Since the wrap seam 3 has been attached, the inner side of the lap joint 3 is soldered 8.
A can body 2 having a sufficient protective coating with the correction paint is obtained, and can bodies using this can body 2 are free from corrosion of the can material due to exposure of the cut end surface at the lap seam and from leakage of iron from the can material to the filled contents. This has the effect of providing a can body with improved can quality without any adverse effects.

[Brief explanation of the drawing]

Figures 1 to 4 show examples of the present invention. Figure 1 is a developed view of a blank, Figure 2 is a partially enlarged view of Figure 1, and Figure 3 is a diagram showing an example of the use of the blank in Figure 1. A perspective view of the prepared can body, Figure 4 is the same as in Figure 3.
5 is a partially enlarged view of a blank according to another embodiment of the present invention, FIG. 6 is a perspective view of a conventional product, FIG. 7 is a developed view of a blank of a conventional product, and FIG. FIG. 6 is a cross-sectional view taken along the - line in FIG. 6; 1... Blank, 2... Can body, 3... Lap seam, 4... Hook seam, 5, 6... Seam lap portion, 8... Solder.

Claims (1)

[Scope of utility model registration request] When forming the blank 1 on the can body 2 in a can body consisting of a lap seam 3 and a hook seam 4 to which the side seam of the can body 2 is soldered, a substantially rectangular or approximately rectangular shape is formed on the inner side of the lap seam 3. The can body is formed by forming a trapezoidal seam lap part 5 in the form of a curved outer peripheral edge, overlapping the seam lap part 6 on the outer surface side of the lap seam 3, and bonding it with solder 8.