JPH07108462B2 - Method for manufacturing thin metal can - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a thin metal can, and more particularly to a method for manufacturing a thin metal can of finite length using an electric resistance welded pipe welding method.

B. Outline of the Invention The present invention uses an electric resistance welded pipe welding method, and particularly, for the purpose of providing a manufacturing method suitable for manufacturing a thin-walled metal can of a finite length, the width of the plate-shaped plate material for pipe forming is adjusted by the electric resistance welded pipe. The dimension is such that the outer peripheral length of the can body can be obtained after welding, and the plate body has a slight residual portion at both edges of the plate width in the length direction of the plate material, at right angles to the length direction of the plate material. Form a kerf with a length dimension as an interval,
This is a method for producing a can body having a finite length by continuously pipe-making the plate material by a continuous pipe making device, and then individually cutting the can bodies from the kerf portion after electric resistance welding. Compared with the metal can manufacturing method, the material can be saved efficiently at high speed.

C. Conventional technology Currently, various containers such as canned cans and juice cans are used on a daily basis, but metal cans are containers that have high strength and can be sealed, and are used for storing foods and many other products. Is widely used as. Thin metal cans with thin cans are available in three-piece cans, which have been widely used to wind up the body and top and bottom lids, and two-piece cans in which the body and bottom are integrated by deep drawing and ironing. Be separated.

Generally, a three-piece can is composed of a can body and two lids, and a lid is double-fastened to a can body to which a flagine is attached to form a container. Among three-piece cans, there are a method for manufacturing a can body as a method for forming a can body and a method for manufacturing a solder can for soldering, which are widely used even now. Fifth
The drawings show the manufacturing process of the above-mentioned solder can, and the outline of the manufacturing method of the solder can will be described with reference to the drawings.

The plate material (tin plate) that will become the can body is cut in the steps (1) and (2) to the individual molding dimensions of the can body, and the corner cut (3) is performed to form the side seam hook (engagement part). , The side seam hooks are engaged with each other after being formed into a cylinder (6), and a solvent (flux) is applied (8) to the side seam as a pretreatment for soldering, and soldering (9) and wiping of excess solder are performed. A can body is formed through the steps (10). A lid manufactured in a separate process is fixed to the can body by double winding to be a product as a can. FIG. 6 (a) is a cross-sectional view of the above-mentioned soldered side seam portion, showing a plate member and a soldered state which are engaged with each other.

On the other hand, unlike the above-mentioned solder can in the method of manufacturing a three-piece can, examples of a method of manufacturing a welding can manufactured by welding include a cono weld method and a wire weld method. The conoweld method is also called squeeze welding.It exposes the base metal of the side seam of the plate material with a special tool, and overlaps this part to concentrate a large amount of heat from the pressurized electrode. The part is electrically welded.

In the wire-fed method, copper can is sent between two flat copper wire electrodes, the side seam corresponding portions are overlapped, and the copper wire electrode pressed by the roller electrode is used as an intermediate electrode to generate heat and pressure of the electrode. Electric welding is effected, and FIG. 6 (b) shows a cross section of the side seam portion of the welded welded can.

D. Problems to be Solved by the Invention Although various manufacturing methods are provided for manufacturing thin metal cans as described above, each manufacturing method has problems that require improvement. The solution was demanded.
Most commonly used in the past, the method of manufacturing a soldering can, in which the side seams are engaged and the side seams are soldered to produce a can copper, requires a large amount of plate material to engage the side seam parts. There has been a demand for saving the plate materials to be used also from the resource saving of the tin plate material which has been widely used.

Also, in the method of manufacturing a welding can in which the side seam of the can copper is pressurized and electrically welded, it is not necessary to interlock the side seam portions, and the size of the overlapping plate material is smaller than that of the manufacturing method by soldering described above. Although the loss is comparatively small, the strength of the can may be affected unless a uniform overlapping portion is maintained, which requires precision in management of the plate material, and the process common to the solder can manufacturing method. Many of the methods require slow pipe making and low production capacity.

As a solution to these problems, it has been attempted to manufacture canned copper by the electric resistance welding method which has been widely used in recent years. Then, in the case of the electric resistance welded pipe welding method, a strip-shaped raw plate is continuously roll-formed into a tubular shape having slit-shaped joints in the length direction, and both edges of the joints are electrically heated. Since it is butt-welded together with this, there is an advantage that there is no overlapping portion in the welded portion, plate-like loss does not occur, and the production rate as a long tube is extremely high. However, on the other hand, a cutting method suitable for cutting a long thin welded pipe into a short pipe at high speed without deforming the welded portion at the cutting portion and without causing much plate-like loss during cutting. It has not been put to practical use because it is a problem.

The present invention has been made in view of the above problems, and makes the loss of the plate material to be used extremely small, the speed of the can making is fast and the finish of the welded portion is good, and the thin-walled metal can of high production capacity is provided. The purpose is to provide a manufacturing method.

E. Means for Solving the Problems The present invention has been made in view of the above problems, and when the can copper of a metal can is manufactured by a continuous pipe forming apparatus equipped with an electric resistance welded pipe welding apparatus, The strip-shaped plate material is characterized by being preliminarily worked, and the specific means used for this purpose is to use a strip-shaped plate material for pipe making supplied to a continuous pipe forming apparatus equipped with an electric resistance welded pipe welding device. , The width of the can is determined so that the outer peripheral length of the can can be obtained after the electric resistance welding, and the length of the can in the longitudinal direction of the plate has a slight residual portion on both edges of the width. Is formed, the plate material is continuously pipe-formed by the continuous pipe forming apparatus, and the can bodies are individually separated by the cut grooves after electric resistance welded pipe welding. .

F. Action By using the above means, the strip-shaped plate material in which the kerf is formed at intervals of the length of the can is formed by the continuous pipe forming device, but is butt-pressed by the electric resistance welding device and the electrical resistance is obtained. Welding is performed to form a continuously welded can body. When welding, the electric current concentrates on the residual portions of both edges of the plate material connecting the can bodies and having a small width, the current flows, the residual portions are overheated and hardened, and easily broken. It can be folded to obtain a can of a predetermined length.

G. Examples Hereinafter, examples of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a main part of a continuous pipe forming apparatus for a thin metal can equipped with an electric resistance welded pipe welding apparatus used in an embodiment of the present invention.

The continuous pipe forming apparatus is a press which is provided near the outlet of the hoop cage portion 2 for smoothly supplying the strip-shaped plate material 1a for thin-walled metal cans, and which forms a groove in the width direction of the strip-shaped plate material 1a. The part 3, the forming part 4 for forming the plate material 1a in a tubular shape, and the squeeze roll 6 for forming the plate material 1a in a tubular shape.
Welder part 5 for electrical resistance welding while pressure welding
And a separating section 8 for separating the tube 1b into one or a plurality of tubes according to the kerf spacing.

The press section 3, which is a main part of the configuration of the present invention, will be described in detail. 2 (a) and 2 (b) show the processing performed on the plate material 1a by the press section 3, and FIG. 2 (a) shows the kerf 1c.
1 shows a plate material 1a on which is formed. The cut grooves 1c are punched out at intervals h in the plate width direction of the plate material 1a having the plate width l. Second
FIG. 2 (b) is an enlarged view of the plate material 1a, in which the kerfs 1c have a small number of kerfs formed by pressing the die provided in the press unit 3.
1c is formed at a right angle to the length direction of the plate material 1a, and the plate width l
There is a small residual width of 1g on both edges. Kerf 1c
Is provided for each interval h, and this interval h is the length dimension of the can body to be made, and similarly, the plate width 1 is set based on the outer peripheral length dimension of the can body. Cut groove 1c
For the groove width of 1 and the residual portion 1g on both edges, various experiments were performed on thin plate materials, and as a result, the kerf 1c to be engraved has a groove width of 0.1 m / m or less and has no burrs, etc. It has been found that a preferable condition for manufacturing a can body is to have a plate thickness of 1a or more and a thickness of 0.8m / m or less. That is, a residual portion 1g having a certain width or more is required as an electric current path at the edge portion when performing electric resistance welding, and on the other hand, in order to facilitate separation of the can body after welding, the residual portion 1g This is because it is determined that the width is preferably smaller.

In this embodiment, the press portion 3 is provided at the outlet of the hoop cage portion 2. However, when the cut groove 1c having the above-mentioned set dimensions is previously formed in the strip-shaped plate material 1a in another step, the press portion 3 is omitted. It is also possible to configure.

Although not added to the configuration of this embodiment, the welder unit 5
It is also possible to add a configuration in which an annealing mechanism, for example, a seam annealer or the like is provided in the subsequent stage to perform annealing or the like of the welded portion.

A method for manufacturing a thin-walled metal can in the continuous pipe manufacturing apparatus configured as described above will be described in detail.

The plate material 1a in which the plate width 1 of the strip-shaped plate material 1a to be supplied is set based on the outer peripheral length dimension of the can body as a product is set on the supply drum of the pipe forming apparatus and supplied to the pipe forming line. Plate material
1a is provided with a margin of material supply to the pipe making line by the hoop cage portion 2, and the press portion 3 arranged near the outlet of the hoop cage portion 2 punches a groove on the plate surface of the plate material 1a to form a kerf 1c. Is formed. As described above, the plate material 1a is punched out at the length dimension h of the can body to be manufactured.
Reaches the forming part 4, and is gradually formed into a circular cross-sectional shape by forming rolls provided in several stages, and is formed into a tubular shape having a slit-like joint in the length direction.

In the welder portion 5, both edges 1e of the seam of the plate material 1a formed in a tubular shape form a V-shaped gap as shown in FIG. 3 (a) and are formed by an inductor 5a connected to a high frequency power source. The welding current I flows through the opposing edges 1e of the V-seam portion and the squeeze roll 6 presses both edges 1e of the seam while locally heating them to carry out welding joining to form the tube 1b. At this time, as shown in FIG. 3 (b),
Since the tubular plate member 1a is diametrically divided at the outer periphery by the kerf 1c, the welding current I flowing through both edges 1e of the V seam portion flows through the residual portion 1g at the portion where the kerf 1c is provided. There is no choice but to make it a road. Therefore, the welding current I concentrates and flows in a small area of the residual portion 1g, and
Is overheated, and the material of the residual portion 1g becomes brittle and fragile even if its ductility is impaired due to coarsening or oxidation of crystal grains.

Further, during welding, both edges 1e of the joint are butted to each other and the tips of both edges 1e are melted and pressure welded together, so the outer peripheral length of the pipe is greater than that before welding as compared to before welding. It is slightly shortened by the size corresponding to. The pressure welding joint margin is determined by the plate thickness of the plate material 1a and welding conditions.

Therefore, the width of the strip-shaped plate 1a is obtained by adding the dimension corresponding to the above pressure welding joint margin to the outer peripheral length of the can body to be manufactured.
With this, it is possible to obtain a can body having a predetermined outer peripheral length dimension after welding. Note that FIG. 4 (b) shows the cross-sectional shape of the butt welded portion after welding.

The tube 1b transferred to the separating part 8 after being welded in the welder part 5 is bent along the cut groove 1c as shown in FIG. 4 by bending the connecting part (residual part 1g) which is easily broken. Easily separated. The above completes the manufacture of the can body as a product.

In the present embodiment, the separating portion 8 has a structure in which the connecting portion of the tube 1b is bent and separated, but it is also possible to use a separating mechanism such as punching that does not cause deformation during separation.

H. Effects of the Invention As described above, the present invention uses a continuous pipe forming apparatus equipped with an electric resistance welded pipe welding apparatus as a method for producing a thin body of a thin metal can, and supplies a plate width of a plate material for a can. And the outer peripheral length of the can body is obtained after welding, and a kerf is provided at both edges of the plate width with a slight residual portion at a right angle to the length direction of the plate, and this kerf is Forming the cans with the length dimension as an interval, and after the electric resistance welded pipes were welded, the respective cans were individually separated by the residual portions, so that the cans are continuously restrained with high productivity by the electric resistance welded pipe manufacturing method. In addition to the above, there is a great effect that after the can is formed, it can be easily separated as a can body of a predetermined length without generating chips or the like according to the kerf and without causing deformation of the cut end.

Since the present invention butt welds the welded portion of the can body,
Unlike the conventional solder can, the cono weld method, and the wire weld method, there are no problems such as requiring a large amount of plate material at the joint or thickening of the joint, so no waste of material occurs and the side of the welded portion does not occur. It is possible to provide products with smooth seams.

[Brief description of drawings]

FIG. 1 shows the essential parts of the embodiment of the present invention, FIG. 2 shows the processing applied to the plate material, and FIG. 3 shows the flow of current flowing through the plate material during electric resistance welding. , FIG. 4 shows the shape of a can-made tube. 5 and 6 show an embodiment according to the prior art. 1 ... band-shaped plate material, 1b ... tube, 1c ... kerf,
1g: Remaining part on both edges, 5: Welder part, 6: Squeeze roll, h: Groove spacing (length of can), l:
Board width.

Claims (1)

[Claims] 1. A strip-shaped plate material for pipe making supplied to a continuous pipe forming apparatus equipped with an electric resistance welded pipe welding apparatus has a plate width which is such that an outer peripheral length of a can body can be obtained after the electric resistance welded pipe welding. With a slight residual portion at both edges, a kerf is provided at a right angle to the length direction of the plate material, and the kerf is formed in the length direction of the plate material at intervals of the length of the can body. A method for producing a thin metal can, characterized in that the plate material is continuously pipe-formed by the continuous pipe-forming apparatus, and after the pipe-making, the residue is cut off to produce individual can bodies.