JP3395453B2 - Method and apparatus for manufacturing metal tapered tube container - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a metal tapered tube container by blow molding using high pressure gas.

[0002]

2. Description of the Related Art Generally, metal tube containers are often used as packaging containers for chemical products such as medicines, adhesives, and paints. This metal tube container is made of a soft and highly extensible metal such as aluminum or tin, and is molded by an impact extrusion process using a press machine. This metal tube container is painted and printed on the surface by a tube maker, shipped with a cap attached, and then sold as a product by filling the contents with a drug or chemical manufacturer.

In the manufacturing process of a metal tube container, a lubricant is applied to a pellet-shaped metal (slag), and the lubricant is interposed between a pair of upper and lower molds, and molded into a cylindrical shape by an impact extrusion process using a press machine. After that, lace processing such as screw formation and dimension adjustment is performed. Next, after annealing (annealing), the steps of inner surface coating, baking, base coating, display printing, cap attachment, pinhole inspection, and sealing are sequentially performed.

The empty metal tube container manufactured as described above has a problem that it cannot be fitted and transported because the body part thereof is cylindrical, and it cannot be carried. For this reason, since the individual pieces are conveyed individually, the transportation cost is high because the air is conveyed. In addition, packaging and packing such as cushioning to prevent crushing of the container during transportation and deformation such as dents is time-consuming, and the transportation and storage costs associated with this are high. The current situation is that the cost is extremely high.

For this reason, the diameter of the body of the metal tube container is expanded in a tapered shape, and a plurality of them are superposedly inserted from the hem opening to form a columnar shape to reduce the occupied volume per unit in the state before filling. Is being considered. As a method of manufacturing this metal tapered tube container, in a process of impact extrusion processing by a press, molding by a mold has been tried, but there has been no successful example. Also, once insert the expansion mandrel, which is a combination of multiple segments, into the inside of the body from the hem opening into a cylindrical tube container, and rotate the expansion mandrel to widen the space between the segments to taper the mandrel. However, a method of mechanically expanding the diameter of the body has been proposed.

However, in this method, the structure of the expansion mandrel is complicated, and the body is mechanically plastically deformed between the expansion mandrel and the outer diameter support portion during the diameter expansion step, so that the printing step is performed. This must be done before, and there is a problem that the extension of the body material that causes pinholes causes unevenness or scratches, resulting in a high defective rate. In addition, this diameter expansion step must be performed before painting, and since the printing is performed on the tapered surface in the printing step, the transfer roller must also be formed in a tapered shape. Technology was required and there were many problems in its practical application.

[0007]

SUMMARY OF THE INVENTION The present invention eliminates the above-mentioned drawbacks and makes it possible to manufacture a high-quality product with few pinholes by expanding the diameter of the barrel portion by a very simple method using high-pressure gas. At the same time, since the diameter is expanded in the state of the cylindrical tube container that has finished the painting and printing processes, it is only necessary to add one process at the final stage of the normal manufacturing process, and the manufacturing method of the metal taper tube container with low manufacturing cost and The manufacturing apparatus is provided.

[0008]

According to a first aspect of the present invention, there is provided a method for manufacturing a metal taper tube container, wherein an inner taper cylinder whose inner diameter increases upward is used as a lower mold, and the inner hollow portion has a cylindrical shape. Insert the metal tube container, which was molded in the above, with the hem opening facing up, and gradually lower the outer diameter toward the tip side, and lower the elastically supported upper die punch to lower the It is characterized in that it is inserted from the hem opening of the processed metal tube container and is closed by the side of the punch, and high-pressure gas is ejected from the punch to gradually expand the body part of the metal tube container in a tapered shape. To do.

Further, in the apparatus for manufacturing a metal taper tube container according to a second aspect of the present invention, an inner taper having an inner hollow portion, the inner diameter of which increases upward, and into which a cylindrical metal tube container to be processed is inserted and inserted. A lower mold formed of a cylinder, the outer diameter of which gradually decreases toward the front end side, the outer diameter of the front end is smaller than the inner diameter of the bottom opening of the metal tube container to be processed, and a high-pressure gas ejection port is provided. In addition, it is characterized by comprising an upper die formed of a punch supported on a punch base via an elastic material.

Further, in the apparatus for manufacturing a metal taper tube container according to a third aspect, the elastic material for connecting the upper die punch to the punch base is a coil spring or a disc spring,
Alternatively, it is characterized by being formed of rubber or the like.

[0011]

According to the present invention, first, a cylindrical metal tube container to be processed is manufactured in accordance with a usual process, and the printing up to this surface is performed. Next, this metal tube container to be processed is inserted into the hollow portion formed in the inner tapered cylinder of the lower mold with the hem opening facing upward. After that, the ram of the press is lowered, and when the tip of the punch reaches the hem opening of the metal tube container to be processed, the high pressure gas is ejected from the high pressure gas ejection port formed at the tip of the upper die to form the tube container. When it is press-fitted into the body of the body, the internal pressure of the pipe rapidly rises and pushes the side wall of the body outward to cause plastic deformation.

When the internal pressure of the pipe further rises, the punch supported by the elastic material is pushed back upward to form a gap between the hem opening of the metal tube container to be processed and the side surface of the punch. The gas blows out and the internal pressure of the pipe drops. When the punch is further lowered, the gap is closed again and the pressure inside the pipe rises, pushing the side wall of the body outward and plastically deforming.When the pressure inside the pipe further rises, the elastic material is compressed and the punch moves upward. When pushed back, high-pressure gas is ejected from the gap to lower the internal pressure of the pipe. When the punch is lowered while slightly vibrating up and down by repeating the same operation, the internal pressure of the tube container gradually increases and decreases, and the internal diameter of the tube gradually expands. The diameter is expanded until it comes into close contact with the surface to form a metal taper tube container.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. In the figure, 1 is a lower mold, 2 is an upper mold inserted inside this, and 3 is a cylindrical metal tube container inserted into the lower mold 2. As shown in FIG. 2, the lower die 1 is formed of an inner tapered cylinder 5 provided with a hollow portion 4 whose inner diameter is increased upward. A base member 6 is connected to the lower portion of the inner tapered cylinder 5, and an ejector pin 7 is attached to the lower portion of the inner tapered cylinder 5 so as to be vertically movable through the base member 6. The lower mold 1 is attached to the bolster of the press by the base member 6, and the ejector pin 7 is connected to an air cylinder (not shown) installed on the lower surface of the bolster.

As shown in FIG. 3, the upper mold 2 has a shaft 11 at the bottom of a punch base 10 attached to a ram of a press.
Are joined to each other, and a disc-shaped engaging portion 12 is provided at the lower end thereof so as to project. Further, a high pressure gas flow passage 13 is formed in the central portion of the shaft 11 along the axial direction thereof, and a lower end portion thereof serves as a high pressure gas ejection port 14. Further, the upper end of the high pressure gas flow passage 13 is formed in the punch base 10 in the lateral direction to form a high pressure gas flow passage.
A high-pressure gas injection port 15 is formed at the end of the high-pressure gas, which communicates with 13.

Numeral 16 is a punch attached to the outside of the shaft 11, and the outer diameter of the punch 16 is gradually reduced toward the tip side.
The outer diameter of the tip portion is formed in a tapered shape smaller than the inner diameter of the hem opening of the metal tube container 3 to be processed. Again punch
A through hole 17 into which the shaft 11 is inserted is opened at the center of the shaft 16, and a recess 18 is formed at the lower end of the through hole 17 to engage with the locking portion 12 attached to the shaft 11. Further, a recess 19 is formed at the upper end of the through hole 17, and a coil spring 20 is attached so as to surround the middle of the shaft 11 here, and the upper portion abuts the bottom portion of the punch base 10 so that the punch 16 elastically moves up and down. It is movably supported.

A method of manufacturing a metal tapered tube container by the above apparatus will be described. First, according to a normal process, a cylindrical metal tube container 3 to be processed is manufactured through press molding of material, lace (screw processing / trimming), inner surface coating, base coating, and display printing. As shown in FIG. 1, the metal tube container 3 to be processed before mounting the cap manufactured in this way is inserted into the hollow portion 4 formed inside the inner tapered cylinder 5 of the lower mold 1 with the hem opening facing upward. To wear.

Next, the ram of the press is lowered, and when the tip of the punch 16 reaches the hem opening of the metal tube container 3 to be processed, the high pressure gas injection port 15 opened in the punch base 10.
High-pressure gas such as nitrogen gas or argon gas, high-pressure air, or a mixed gas thereof is supplied from the high-pressure gas through the high-pressure gas flow passage 13 and is ejected from the high-pressure gas ejection port 14 at the lower end of the shaft 11, It is pressed into the body of the processed metal tube container 3. The high-pressure gas that is press-fitted at this time creates a gap between the punch 16 and the opening of the tube skirt, and blows out from this gap. When the upper mold 2 is further lowered, this gap is closed, and the pipe internal pressure rises sharply to push the side wall of the body outward and plastically deform it.

When the internal pressure of the pipe further rises, the punch 16 elastically supported by the coil spring 20 compresses the coil spring 20 and pushes it back upward, and the punch 16 and the hem opening of the metal tube container 3 to be processed again. A gap is formed between the inner side surface and the side surface, and high-pressure gas is ejected to the outside to reduce the internal pressure of the pipe. When the punch 16 is further lowered, the gap is closed again and the pressure inside the pipe rises to push the side wall of the body outward and plastically deform, and when the pressure inside the pipe further rises, the coil spring 20 is compressed to shrink the punch 16. Is pushed back upward to form a gap, from which high-pressure gas is ejected to the outside to lower the internal pressure of the pipe.

The same operation is repeated thereafter, and the vertical vibration of the punch 16 causes the internal pressure of the tube container 3 to rapidly increase and decrease, and the internal diameter of the tube gradually increases as shown in FIG. The metal tube container 3 is expanded in diameter until it comes into close contact with the tapered inner surface of the hollow portion 4 of the lower mold 1.

When the upper mold 2 reaches the bottom dead center as shown in FIG. 4, the metal tube container 3 to be processed is brought into close contact with the inner wall of the inner tapered hollow portion 4 of the lower mold 1 and its outer diameter is restricted. The metal taper tube container 21 is molded. When the upper mold 2 turns upward, the metal taper tube container 21 is separated from the punch 16 by the high pressure gas and remains in the lower mold 1. Punch
When 16 is removed from the lower mold 1, the ejector pin 7 driven by the air cylinder becomes a metal taper tube container.
The neck of 21 is pushed up, separated from the lower mold 1, and eliminated. This series of steps is completed in 0.4 to 0.8 seconds and can be molded in an extremely short time.

The blow-molded metal taper tube container 21 has a cap 22 attached to its neck as shown in FIG. Then, it is packaged and shipped. In a chemical maker or a chemical maker, the stacked metal taper tube containers 21 can be set in the filling machine as they are and sequentially removed one by one from the tip side for filling, so that the filling device can be downsized. .

In the present invention, it is assumed that a coil spring is used.
When the upper die 2 is a fixed type in which the punch base 10 and the punch 16 are integrated, the body part of the metal tube container 3 to be processed is buckled, and the tube container 3 is omitted. The hem of the will make a popping sound and tear as if it were torn in the axial direction. Further, even if the upper mold 2 is slowly lowered, a gap for escaping the injected high-pressure gas is not formed, and therefore the outer peripheral portion of the punch 16 and the inner wall of the skirt portion of the tube container 3 are pressed against each other, and there is no lubrication. Buckling and fracture occur.

Therefore, according to the present invention, the punch 16 is elastically supported by the coil spring 20, and the coil spring 20
By virtue of the balance between the elasticity of the injection and the pressure of the injected high-pressure gas, the punch 16 is slightly vibrated at a high speed to form a gap through which the injected high-pressure gas escapes. Blow molding is possible by gradually increasing the diameter while preventing an increase in internal pressure. In this blow molding, the inner and outer surfaces of the metal tube container 3 to be processed are punched in the process of plastic deformation using high pressure gas.
Since the diameter is expanded without contacting the 16 or the hollow part 4, unevenness or scratches may occur in the extension of the body material compared to the conventional method of plastically deforming using an expansion mandrel. It is possible to mold a good product that has no pinholes and no damage on the printed surface.

Further, according to the present invention, since the high-pressure gas layer acts as a lubricant, a lubrication step for plastic working is not required,
It has the advantage of not requiring a lubricant removal step after the diameter expansion process,
Since the diameter of the standard metal tube container 3 to be processed after the printing process is expanded, only one process needs to be added at the final stage of the normal manufacturing process, and the equipment cost and the manufacturing cost can be reduced.

In the above embodiment, the coil spring 20 is interposed between the punch base 10 and the punch 16, but a structure using an elastic material such as a disc spring or rubber may be used. The shape of the punch 16 is the hollow portion 4 of the lower mold 1.
It does not have to be similar to the inner diameter shape of, but the point is that the punch 16 has a conical shape or a shell shape in which the maximum diameter exceeds the inner diameter of the product, and the taper angle is obtuse than the inner diameter taper angle of the hollow portion 4 of the lower mold 1. If there is, the metal tube container 3 to be processed is pressed against the inner wall of the hollow portion 4 by the injected high-pressure gas, and is expanded and shaped faithfully to the inner diameter shape dimension of the hollow portion 4 regardless of the shape dimension of the punch 16.

[0026]

As described above, according to the present invention, by blow molding using a high-pressure gas, the body portion of the metal tube container to be processed is expanded in a tapered shape to manufacture a high-quality product with few pinholes. In addition to being able to do it, the diameter of the cylindrical tube container that has been painted and printed is expanded, so there is no damage to the printing surface and only one process is required at the final stage of the normal manufacturing process. It is possible to obtain the manufacturing method of the tapered tube container and the manufacturing apparatus thereof.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an apparatus for manufacturing a metal taper tube container showing a state in which a metal tube container to be processed is inserted into a lower mold and the lower mold is lowered according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of the lower mold shown in FIG.

FIG. 3 is an enlarged cross-sectional view of the upper mold shown in FIG.

FIG. 4 is a cross-sectional view showing a manufacturing apparatus in which the upper die is lowered from the state shown in FIG. 1 to mold a metal tapered tube container.

FIG. 5 is a graph showing a relationship between a pipe inner pressure and a pipe diameter according to the manufacturing method of the present invention.

FIG. 6 is a front view showing a state in which metal taper tube containers manufactured according to the present invention are stacked.

[Explanation of sign]

1 Lower mold 2 Upper mold 3 Processed metal tube container 4 hollow part 5 Inner taper cylinder 6 Base member 7 ejector pin 10 punch base 11 shaft 12 Locking part 13 High-pressure gas flow passage 14 High-pressure gas jet 15 High pressure gas inlet 16 punches 17 Through hole 18 recess 19 recess 20 coil spring 21 metal taper tube container 22 cap

Continuation of the front page (56) Reference JP-A-7-308722 (JP, A) JP-A-63-137520 (JP, A) JP-A-6-238380 (JP, A) JP-A-60-118339 (JP , A) JP-A-2-290630 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B21D 51/36 B21C 37/18 B21D 26/02 B21D 39/08 B21D 41/02

Claims (3)

(57) [Claims] 1. An inner taper cylinder whose inner diameter increases upward is used as a lower mold, and a metal tube container to be machined into a cylindrical shape is inserted into this inner hollow part with the bottom opening of the metal tube container facing upward. The outer diameter is gradually reduced toward the side, and the upper die punch elastically supported is lowered,
Characterized by inserting from the hem opening of the metal tube container to be processed and closing it with the side surface of the punch, ejecting high pressure gas from the punch and gradually expanding the body part of the metal tube container in a tapered shape And a method for producing a metal tapered tube container. 2. A lower die formed of an inner tapered cylinder having an inner hollow portion, the inner diameter of which increases upward and into which a cylindrical metal tube container to be processed is inserted, and a lower die facing the tip side. The outer diameter is gradually reduced, the outer diameter of the tip is smaller than the inner diameter of the bottom opening of the metal tube container to be processed, a high-pressure gas ejection port is provided, and the punch base is supported via an elastic material. An apparatus for manufacturing a metal taper tube container, which comprises an upper die formed by a punch. 3. The metal taper tube container according to claim 2, wherein the elastic material for connecting the upper punch to the punch base is formed of a coil spring, a disc spring, or rubber. Manufacturing equipment.