JPH0741329B2 - Metal container manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a metal container, and more particularly to a method for manufacturing a so-called narrow mouth container in which the inside is sealed with a lid or a valve device, and an aerosol container or a beer can. Can be used for beverage containers such as.

Then, the present invention improves the combination procedure of ironing and drawing to move the decorative coating (H) formed on the body of the semi-finished container having a hollow body to the diameter reducing portion. In particular, the surface condition of the diameter-reduced portion near the mouth where the surface is wavy is improved and the color tone of the decorative film (H) formed by painting or printing is improved, and the surface condition of the sealed container is covered over the entire area. To improve.

[Prior Art and its Problems] In a sealed container such as an aerosol container, as shown in FIG. 9, a lid body (2) equipped with a valve device (B) is attached to the upper end of a container body (1). Has become. The mouth (11) of the container main body (1) on which the lid (2) is mounted is usually smaller than the diameter of the body, and the body (1) is connected to the mouth (1).
It has a taper (12) until 1).

With such a configuration, when the sealed container is packed, there is an advantage that many parts can be accommodated in the packing box body without interfering with the caulking stop portion of the peripheral edge of the lid body (2), and the caulking is performed. There is an advantage that the acting force of the internal pressure of the container acting on the stopper is reduced.

However, in the case of the conventional sealed container of this type, the finished state of the container surface, particularly the finished state of the tapered portion (12) is insufficient, and the surface is not smooth when subjected to surface treatment such as painting. Will be things.

This is due to the manufacturing method of the container main body (1). Here, the conventional manufacturing method will be described in detail.

In the case of the conventional container-based body (1), a cylindrical body with a bottom as shown in FIG. 10 is once manufactured by drawing or ironing. Next, the upper end open portion of the container is reduced by necking to form a narrow mouth having the structure shown in FIG. 11, and the opening end is curled, and the lid body (2) is caulked to the curling portion (C). A sealed container as shown in FIG. 9 is completed.

In the case of this manufacturing method, the taper portion (12) is formed during the necking process. However, in this necking process, the degree of diameter reduction is limited to a certain ratio or less, so In order to sufficiently reduce the mouth part with respect to the part diameter, this necking process needs to repeat a plurality of steps. Then, a boundary portion is generated in each step of the necking process, and wrinkles or waviness is generated in the tapered portion (12) in the number corresponding to the number of steps of the necking process. Also, since the necking process is to reduce the diameter only by the outer die, the work portion is not precisely formed in close contact with the inner surface of the outer die at the time of this working, and the cross section of the work portion is There is a tendency to bend inward too much, and in this respect also, the smoothness of processing is insufficient.

Further, in the case of the hermetically-sealed container processed and formed as described above, the decorative film (H) is formed on the container body and the tapered portion (12) by painting after forming the entire shape. When forming this decorative film (H), the container body and the tapered portion (12) are usually coated separately, and the cosmetic film (H) formed on the outer peripheral surface of the container is tapered with the body. There is a problem that it is slightly different from the department (12). This is a problem that inevitably arises from painting the two parts separately.

[Problem] The present invention provides a method for manufacturing such a sealed container,
In order to improve the finished state of the surface of the sealed container in the completed state, and to make the decorative film (H) of the container body and the tapered portion (12) have the same color tone, in particular, the tapered portion (12) It is an object of the invention to prevent wrinkles and waviness from being generated in the above-mentioned part and to form the same figurative film in the body and the tapered part by forming the decorative film (H) once.

[Technical Means] The technical means of the present invention taken to solve the above-mentioned technical problem is that "a container with an open lower end is manufactured by a combination of drawing and ironing, and the final step of manufacturing this container is Is to be finished into a hollow container having a predetermined diameter and depth by ironing, and a decorative film (H) is formed by painting or printing in a required range over a certain range from the upper end of the trunk of the hollow container, and then the hollow container. The top part of the body is drawn by using a die consisting of a punch (51) and a die (52) to form a tapered part (12) at the upper end of the body and a protruding part is formed at the upper end of this tapered part (12). Then, the upper end of the tubular container is moved to the tapered portion by the drawing process, the top wall of the protruding portion is cut and removed, and the rising portion (13) is formed at the small diameter end of the tapered portion (12). The lid (2) is caulked by using the rising portion (13), while the bottom plate (3) is provided at the lower end open portion of the short container.
I tried to stop the caulking. "

[Operation] The above technical means of the present invention operates as follows.

The body surface of the container in the completed state is finished in a mirror state because the final step is formed by ironing. Further, the tapered portion (12) formed from the upper end of the body portion to the mounting portion of the lid body (2) is formed by drawing using the punch (51) and the die (52).
The taper portion (12) is formed by the punch (51) and the die (5).
The final shape is finished in a state of being in close contact with the machining die portion of 2), and the taper surface of the machining die portion has a smooth tapered surface. Also, a cosmetic film (H) formed over the range from the body of the container to the taper (12).
Is formed over a certain range from the upper end of the barrel in the state of a hollow container, and a decorative film (H) is formed by one surface treatment such as painting, which is the tapered portion from the barrel after completion of molding. It will be located over (12).

In the case of the hermetically-sealed container manufactured by the above method, the container with the lid body (2) attached thereto is caulked before the bottom plate (3) is caulked, or with the bottom plate (3) attached. The contents are filled prior to the crimping of the lid body (2).

[Effects] The present invention having the above-described configuration has the following unique effects.

The barrel of the finished container is finished in a mirror-like shape, and the taper part (12) following it is finished in a smooth taper surface, so that the entire surface of the container main body (1) is improved compared to the conventional one. Will be things.

Further, after the container is completed, the decorative film (H) such as painting is not formed, but the decorative film (H) integrally formed in one step is moved to the taper portion (12) side,
Since the decorative film (H) is formed from the body part to the tapered part of the finished container, the decorative film (H) has the tapered part (12).
It is possible to prevent the inconvenience that the color tone and the like are slightly different between the body and the body. In other words, there is no need for color matching. Further, since the tapered portion (12) has a uniform surface, the finish of the decorative film (H) in this portion is also improved.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 8.

The hermetically sealed container of this embodiment has a structure as shown in FIG. 1, and the container main body (1) is composed of a hollow cylindrical body and a bottom plate (3) attached to the lower end open portion. Then, the cylindrical body and the bottom plate (3) are manufactured by using a so-called composite metal plate in which a protective film (L) made of synthetic resin is formed on one surface of a steel plate (K) as shown in FIG.

In manufacturing this hollow container, first, a cup-shaped container with one end open as shown in FIG. 3 is manufactured by drawing,
The protective film (L) is formed so as to be located on the inner surface side.

Next, this cup-shaped container is made into a hollow container (hereinafter referred to as a semi-finished container (10)) whose lower end is open as shown in FIG. At this time,
In the ironing process, as shown in FIG. 4, the work piece is pushed into the die (D) by the punch (P), and the body part is stretched in the axial direction with the body part thickness reduced. To be done. Therefore, the surface state of the die (D) corresponds to the finished state of the inner peripheral surface of the die (D). Since the surface of the processed portion of the die (D) is finished in a mirror state, the body surface of the semi-finished container (10) is finished in a mirror state by the ironing process.

Next, the decorative film (H) is formed in a certain range from the upper end of the body of the semi-finished container (10) molded as described above by a method such as painting or printing. When the decorative film (H) is formed by painting, as shown in Fig. 5, the coating roll (R) is brought into contact with the body and the jig (J) inserted from the lower end opening of the semi-finished container is rotated. While applying the paint.
At this time, since the jig (J) is inserted from the lower end open portion of the semi-finished container (10) and supports the inner surface of the body in a paired state, this supporting state is stable. Further, since the jig (J) is rotated for coating, the efficiency of the coating work can be improved.

Then, the upper part of the semi-finished container (10) is projected from the taper part (12) continuing to the body part using the punch (51) and the die (52) as shown in FIG. 6 and the small diameter part at the upper end. Draw it so that it becomes the protruding part (15).

Here, the punch (51) is formed with a working die part (53) conforming to the inner surface shapes of the taper part (12) and the projecting part (15) from the upper end of the body part of the completed container, and the other die. (Five
In 2), there is formed a working die part (54) conforming to the shape of the outer surface in the range from the upper end of the body part of the completed container to the rising part (13) of the projecting part (15). The degree of processing by this drawing is set to a predetermined value so that a part of the upper end of the body of the semi-finished container (10) is drawn into the taper part (12). When the top of the semi-finished container (10) is drawn using the punch (51) and the die (52), as shown in FIG.
A taper part (12) and a protrusion part (15) are formed at the upper end of the semi-finished container (10). During this process, the taper part (12) and the rising part (13) are finally
Since the punch (51) and the die (52) are plastically worked in such a state that they are clamped between the working die part (53) and the working die part (54), both the inner surface and the outer surface of this section are machined. The surface condition of the mold part (53) and the working mold part (54) is matched.

For reference, if the diameter of the body of the finished container is 40 mm and the diameter of the minimum diameter part of the taper part (12) and the rising part (13) is 25 mm, the depth of this rising part (13) is 11 mm. If set to a degree, the upper end of the body of the semi-finished container will just move to the tapered portion (12) by drawing.

As described above, the decorative coating (H) is formed from the taper (12) to the body and the protrusion (15) is formed on the top of the tapered portion. The top of the protrusion (15) of the semi-finished container is cut and removed. Then, only the rising part (13) is projected to the small diameter end of the taper part (12), and the container main body (1) is curled to curl (C) the small diameter end part of the taper part (12). ) Is formed. Since the rising portion (13) which is the curling portion is only formed by drawing or bulging, the thickness of this portion does not have unevenness, and the thickness is cup-shaped in the initial stage. The thickness is approximately the same as or slightly thinner than the thickness of the container as manufactured. Therefore, even during the curling process, the curling portion (C) having a smooth surface can be formed by curling without difficulty.

Next, the bottom plate (3) is attached to the lower end opening of the semi-finished container (10) in the above state. Then, as this mounting method, a combination of adhesion and crimping is adopted.

Therefore, in this embodiment, as shown in FIG. 8, a bottom plate (3) in which a skirt portion (31) is connected to the periphery of a shallow spherical bottom portion (30) is provided in a semi-finished state with both ends open. Insert into the open bottom of the strip, but prior to this, complete the semi-finished container (1
The adhesive is applied to the vicinity of the lower end open part of (0) over the entire circumference, and the skirt part (31) coincides with this application area and the lower end of the skirt part (31) is a semi-finished container (10). Insert the bottom plate (3) to a position located inward of the lower end of the body of the skirt (31) and, in this state, the lower end of the skirt (31) and the semi-finished container (10).
Curling the lower end of the torso of the body to prevent crimping. Then, as shown in FIG. 1, the bottom end open part of the semi-finished container (10) is closed by the bottom plate (3) and the airtightness between the skirt part (31) and the inner circumference of the body of the semi-finished container (10) is secured. It has been done. As the constituent material of the bottom plate (3), the same composite steel plate as the constituent material of the container main body (1) is used.

Here, when the inside of the container is pressurized during the curling, the adhesive which tends to gather around the peripheral portion of the bottom plate (3) when the bottom plate (3) is inserted is semi-finished together with the skirt portion (31). It becomes easy to enter during chamfering of the inner peripheral portion of the container (10), and the adhesion is ensured. Particularly, when the tip end of the cross section of the curling portion (C) is made to bite into the inner surface portion of the skirt portion (31), the semi-finished container (10) formed by the above-mentioned adhesion.
The skirt portion (31) and the bottom plate (3) are joined by a mechanical connection other than the connection between the bottom plate (3) and the bottom plate (3),
The mounting strength of the bottom plate (3) is increased. The same effect is exhibited when the skirt portion (31) and the lower end of the body of the semi-finished container (10) are both curled.

At the upper end of the container body (1) manufactured as described above, a mouth portion having a curling portion (C) is opened, and the contents are filled from this mouth portion to cover the mouth portion. When (2) is crimped in the same manner as the above-mentioned conventional example, a container in which the contents are sealed is completed.

[Brief description of drawings]

FIG. 1 is a sectional view of a sealed container having a container body manufactured by the method of the present invention, FIG. 2 is an explanatory view of materials used in an embodiment of the method of the present invention, and FIG. 3 is a drawing of the first step. Fig. 4 is an illustration of a cup-shaped container manufactured by processing, Fig. 4 is an illustration of ironing process, Fig. 5 is an illustration of coating process, and Fig. 6 is gold for forming protrusions and taper (12). FIG. 7 is an explanatory view of a mold, FIG. 7 is an explanatory view of a semi-finished container in which a tapered portion and a protruding portion are formed on the top, and FIG. 8 is a sectional view of a bottom plate (3), and FIG.
Fig. 11 to Fig. 11 are explanatory views of a conventional example, in which, (51) ... punch (52) ... die (12) ... taper part (13) ... rising part (2) ... lid (3) …… Bottom plate (H) …… Makeup film

Claims (1)

[Claims] 1. A cylindrical container having an open lower end is manufactured by a combination of drawing and ironing, and the final step of manufacturing the cylindrical container is to finish it into a cylindrical container having a predetermined diameter and depth. A decorative film (H) is formed by painting or printing over a certain range from the upper end of the body of the container, and then the top of the container is squeezed using a die consisting of a punch (51) and a die (52). A tapered portion (12) is formed at the upper end of the barrel portion by working, and a protruding portion is formed at the upper end of the tapered portion (12), and the upper end portion of the hollow container is moved to the tapered portion by the drawing work, and the protruding portion is formed. The top wall is cut off to form a rising portion (13) at the small diameter end of the tapered portion (12), and the lid body (2) is caulked with the rising portion (13), while container The lower end opening, a bottom plate (3)
A method for manufacturing a metal container, which is designed to be caulked.