JPS6397322A - Necking work method and its die - Google Patents

Abstract

PURPOSE:To secure a sufficient necking amount by providing a desired clearance between a guide part provided on the inner surface of a bending die of the upper die and a work holder provided on the inner side of the bending die, by making up a neck part in the state of restricting the side wall of a fed metal vessel. CONSTITUTION:When the reduced metal vessel by drawing is loaded on a lower die 14 and a ram are descended, the upper die body 21b is abutted on a holding ring 15 and the bottom of the vessel is pushed on the lower die 14 by a holding plate 27. As the upper die plate 19 is descended further, an urethane spring 22 is deformed to contact an auxiliary plate 19b fast to an upper die holder 21a. At this time, a core metal 20 is cut into a work holder 25 to open in four directions, the clearance is formed according with the width of the side wall of the vessel between the guide part of the bending die 21 and the holder 25. Succeedingly, an urethane spring 18 is starting to deform, at this time, the side wall of the vessel is bent through said clearance to be pressed and bent by a part of the necking work 24, the necking part is formed. In this way, the neck part with sufficient necking amount and free from winkles can be formed.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a necking method used when reducing the diameter of the opening edge of a metal container by press working to form a neck portion of a predetermined shape. Regarding molds and molds.

(Prior art) Metal containers for packaging are provided with lids on the openings of the container bodies for various purposes, but due to this structure, in some scales with capacity 8, the entire circumference of the opening is reduced in diameter by press working. Then, the neck portion is formed. In this necking process, the opening edge of the container body is pressed from the outside and is reduced in diameter to fit the inside of the lid 2, as shown in FIGS. 6(a) and 6(b), thereby forming the neck portion 3.

(Problem to be solved by the invention) In the conventional necking process, from the mold's 4 parts to the container body 1
The opening edge of the neck is only pressed from the outside, and the inside remains free from the beginning to the end of processing, which causes wrinkles to appear in the neck portion where the dimensions gradually shrink. Further, there is a problem in that there are great restrictions on increasing the neck G in consideration of the occurrence of wrinkles during shrinkage.

In general, if the neck length is limited, the neck cannot be bent at an acute angle, so Figures 6 (a) and (b)
), when the container body 1 and the lid 2 are combined, a large gap C occurs in the neck 3, and sometimes the integrity of the designs A and B drawn on the container body 1 and the lid 2 is interrupted. This can lead to loss of appearance, greatly deteriorating the aesthetic appearance.

Furthermore, in a metal container for packaging, it is necessary to protect food such as chocolate contained therein from moisture, but the larger the gap C, the less airtight it is, which is not preferable.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an improved necking method and a mold thereof, which can ensure sufficient neck suspension for bending at an acute angle, and which does not cause defects such as wrinkles in the neck part. There is a particular thing.

[Structure of the invention]

(Means for Solving the Problems) The necking method according to the present invention uses a guide portion formed on the inner surface of the bending mold of the upper mold and a workpiece holder provided inside the bending mold to form a metal container. A gap of approximately the same width as the thickness of the side wall is formed around the entire circumference, and then the side wall of the metal container is fed into the gap sequentially from the edge of the mouth to form a neck portion of a predetermined shape at a length of 1 m with the entire side wall restrained. It is characterized by being molded.

Further, the necking mold of the present invention includes a lower mold and an upper mold configured to be able to be divided into upper and lower parts, and the lower mold is placed on a lower mold plate and fixed to support a metal container on its upper surface. It is movable in the vertical direction together with a lower mold and a bin plate that is in contact with the side of the fixed lower mold, surrounds the entire rIA foot mold, and is disposed below the lower mold plate via a plurality of bin members. and a presser ring provided on the lower side of the bin plate, which shrinks in the vertical direction when the bin plate and the presser ring are lowered in conjunction with the movement of the ram of the press device, thereby changing the position of the presser ring. The upper mold has an upper mold plate having a mandrel in the center thereof, and a plurality of elastic pressurizers located on the lower side of the upper mold plate, the upper surface of which is connected to the lower surface of the upper mold plate. are arranged at a constant distance of 111 ft across the body, and are provided so that when the elastic body is compressed and deformed, the distance is shortened and the upper surface thereof is brought into close contact with the lower surface of the upper die plate, and a bending mold having a necking part on the inside thereof for forming a desired neck part on the metal container, and the mandrel provided inside the bending mold and moving downward as the upper mold plate moves downward. and a workpiece holder that is expanded in all directions to restrain the movement of the side wall of the metal container from the inside, and the acting force accompanying the restoration of the elastic deformation between the lower pressurizing device and the elastic body is The lower pressure device is characterized in that the lower pressure device is configured to have a value that is larger than the elastic body by a certain value.

(Function) The bottleneck in necking processing is that when processing force is applied from the outside to the opening edge of the metal container to be processed, this pressing force cannot be reliably supported inside the metal container.

Therefore, before starting the necking process, it is necessary to create a condition that can support the pressing force on the inside.The first step is to form a guide part on the inner surface of the upper mold and a step ( ) Creates a gap around the entire circumference with a workpiece holder that is approximately the same width as the side wall of the metal container. Thereafter, the side walls of the metal container are sequentially fed into the gap starting from the edge of the mouth. At this time, the side wall fed into the gap is pressed and bent inward by the necking part formed on the inner surface of the bending die. During this time, the movement of the side wall is restricted from the inside at a portion below the shoulder of the work holder.

Then, when the side wall is fed further, the side wall is bent at the base of the shoulder of the work holder. During this time as well, the side wall is restrained from the outside by the necked portion. As the side wall progresses further, the side wall, which is restrained from the inside and outside by the hanging wall above the necking part and the hanging wall above the shoulder of the work holder, is formed into a vertical shape connected to the neck part.

(Example) Hereinafter, the present invention will be explained along with an example of a mold shown in FIGS. 1 and 2.

In FIG. 1, the mold consists of a lower mold, generally designated by numeral 11, and an upper mold, generally designated by numeral 12.

First, to explain this lower mold 11, the lower mold 11 has a lower mold plate 13 as a central element, and this lower mold plate 13.
It has a fixed lower die 14 formed to a size such that the metal container to be processed is placed on the upper surface thereof. The circumference of the fixed lower mold 1/l is supported by a holding ring 15, and this holding ring 15 is supported by a plurality of bin members supported by a bin plate 16 placed below the lower mold brakes 1 to 13. 17 from below. Further, a lower pressurizing device, for example, a urethane spring 18, is provided on the lower side of the bin plate 16 in contact therewith. In addition, this urethane spring 1
8 utilizes the acting force accompanying the restoration of elastic deformation as pressure.

Next, the upper mold 12 will be explained.

Reference numeral 1 indicates an upper mold plate that moves together with the ram. This upper mold plate 19 is separated from a main pressure plate designated by 19a and an auxiliary plate designated by 19b. A mandrel 20 is vertically disposed at the center of one of the upper mold plates so as to be connected to the lower surface of the earth pressure coupler plate 19a, and a mandrel 20 is formed so as to move in accordance with the movement of the upper mold plate 19.

Further, an auxiliary plate 19b is provided on the lower side of the upper die plate 19.
A bending die 21 is provided with a constant spacing between the two.

This bending die 21 includes an upper die holder indicated by the symbol 21a,
It consists of an upper mold main body indicated by reference numeral 21b. A plurality of elastic bodies, such as urethane springs 22, are interposed between the upper mold holder 21a and the auxiliary plate 19b, and a certain pressure is generated between the two using the restoring force given by elastic deformation. There is. Note that the acting force of this urethane spring 22 is the same as that of the urethane spring 1 described above.
This value is smaller than the acting force of 8.

Further, on the inner surface of the upper die body 21b of the bending die 21, a guide portion 23 is formed to match the outer edge of the side wall of the metal container to be processed, and a necking portion 24 is formed to follow the shape of the neck portion. is formed. Further, a work holder 25 is provided at the center of the bending die 21 concentrically with the center of the mandrel 20. The workpiece holder 25 is configured in a cross shape as shown in FIG.

On the other hand, returning to FIG. 1 again, a presser plate 27 is provided at the tip of the two springs 26 that are vertically movable inside the mandrel 20.

Note that @28 in the figure is a spring, 2 are set screws, and 3
0 indicates Pol 1~, respectively.

Necking processing using the mold configured as described above is performed in the following steps.

That is, in FIG. 1, the punched and drawn metal container is placed on the fixed lower die 14. It does not show rfE,
When the ram of this ↑9 brace neck descends, the upper mold body 21
The lower surface of b contacts the upper surface of the presser ring 15, while the presser plate 27 inserted through the opening of the metal container presses the bottom of the metal container against the fixed lower mold 14. If the ram continues to descend, the urethane spring 18 will release the presser ring 1.
5 supports the bending die 21 in a position where it remains in contact with the bending die 21, the urethane spring 22 starts deforming, and the upper die plate 19 comes down together with the mandrel 20. Finally, the urethane spring 22 is completely collapsed, and the lower surface of the auxiliary plate 19b and the upper surface of the upper die holder 21a are brought into close contact. At this point, the position of the mandrel 20 is lowered by an amount corresponding to the gap when the auxiliary plate 19b and the upper mold holder 21a were initially separated, and the workpiece holder 20 is moved downward in order to break the workpiece holder 25 and enter the workpiece holder 25. move in all directions, and a gap with a width matching the thickness of the side wall of the metal container is formed between the guide portion 23 formed on the inner surface of the bending die 21 and the workpiece holder 25.

After this, when the ram lowers J3, the urethane spring 1
8 begins to deform, and the presser ring 15 is pushed by the upper mold body 21b and moves downward along with the bin plate 16. At this time, the side wall of the metal container opens I! When the ram enters the gap from the end and is still lowered, the side wall is pressed by the necking part 24 formed on the inner surface of the bending die 21 and bent inward, forming a neck part. When the ram reaches its lowest point and forms the desired neck, the pressure that was causing the ram to move downward is released, causing it to reverse and rise. By releasing this pressure, the deformed urethane spring 18 pushes up the bin plates 1 and 16, and returns the retainer ring 15, which is integrated with the bin plates 1, 16, to its initial position. As the presser ring 15 moves, the bending mold 21
The upper mold brakes 1 to 19 also rise. If the upper limit of the ram continues, the deformed urethane spring 22 also returns to its original state, so the bending die 21 and the upper die plate 19 are separated, and the upper die plate 19 rises together with the mandrel 20. However, the bending die 21 remains in that position. At this time, the workpiece holder 25 is closed by the upper back of the mandrel 20, and the holder plate 27 attached to the tip of the spring 26, which is biased by the spring 28, holds the metal container.
Jump out more. Then, the ram returns to its original position and the necking process is completed.

If the necking process is proceeded in this manner and according to the above procedure, the pressurizing force acting from the outside is supported on the inside of the metal container, and the generation of wrinkles is reliably prevented. Also,
It is possible to sufficiently prevent neck hanging, and by using an appropriate bending die in a post-process, a neck portion bent at an acute angle can be obtained.

Note that the mold used in the necking method of the present invention is not limited to the above embodiment.

FIG. 4 shows another method for removing the metal container of the necked note. That is, in this embodiment, an elastic body that biases the bouncing rod 31, for example, the urethane spring 3, is used.
2 is the main pressure plate 33a constituting the upper die plate 33;
and the auxiliary plate 33b via the plate 34. Note that the reference numeral 35G in the figure indicates a bolt that supports the workpiece holder 37 inside the bending die 21 via the plate 36. Further, the reference numeral 38 is a bush.

Further, FIG. 5 shows another embodiment of the work holder.

That is, here, the work holder 398, 39b is divided into eight parts, and the mandrel 20 is connected to the work holder 39 in the same manner as in the above embodiment.
a, 39b is expanded when it is cut into the bending mold 2.
A gap is formed between the guide part 23 formed on the inner surface of the guide part 1.

Further, in the above embodiment, the urethane springs 18 and 22 are made of urethane material, but they may be made of a material that utilizes elastic deformation, such as synthetic rubber, and may also be made of a material that utilizes elastic deformation. A similar function can be obtained even if it is constructed from parts.

〔Effect of the invention〕

As explained above, in the present invention, a gap r7B of approximately the same width as the thickness of the side wall of the metal container is created around the entire circumference by the guide portion formed on the inner surface of the bending die of the upper die and the workpiece holder provided inside the bending die. After that, the side wall of the metal container is fed into the gap sequentially from the mouth edge to form a neck portion of a predetermined shape while the entire side wall is restrained.
It is possible to have a wide range of neck suspensions, and there are no defects such as wrinkles in the neck, making it excellent and useful.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a mold applied to the necking method according to the present invention, and FIG.
A sectional view taken along line 1f, FIG. 3 is a process explanatory diagram showing the machining state using the mold shown in FIG. 1, and FIGS. 6(a> and (b) are explanatory diagrams showing gaps, etc. that occur in the neck portion of a conventional metal container. 1...lower mold, 12...upper mold). Mold, 13... Lower mold plate, 14... Fixed lower mold, 15... Presser ring, 16
...Bin plate, 17...Bin member, 18.22
．． 32... Urethane spring, 19.33... Upper mold play i~, 19a, 33a-... Main pressure plate,
19b, 33b... Auxiliary play 1-120... Core metal, 21... Bending mold, 21a... Upper mold holder, 21b
... Upper mold body, 25°39... Work holder, 26.
31...Bounce bar, 27...Press plate, 30.3
5...Bolt, 34...Play 1~.

Claims (1)

[Claims] 1. When necking a metal container using a mold consisting of a lower mold and an upper mold that can be divided into upper and lower parts, a guide is first formed on the inner surface of the bending mold of the upper mold. A gap with a width approximately equal to the thickness of the side wall of the metal container is formed around the entire circumference by a workpiece holder provided inside the bending die, and then the side wall of the metal container is sequentially bent from the opening edge to the above. A necking processing method characterized by forming a neck portion of a predetermined shape while feeding into a gap and restraining the entire side wall. 2. A lower mold and an upper mold configured to be able to be divided into upper and lower parts; a presser ring that is in contact with a side portion, surrounds the entire fixed lower mold, and is provided so as to be movable in the vertical direction together with a pin plate disposed below the lower mold plate via a plurality of pin members;
A lower pressurizing device is provided below the pin plate and contracts in the vertical direction when the pin plate and the presser ring are lowered in conjunction with the movement of the ram of the press device, thereby determining the position of the presser ring. The upper mold includes an upper mold plate having a mandrel in the center thereof, and an upper mold plate located below the upper mold plate, the upper surface of which is spaced a certain distance from the lower surface of the upper mold plate via a plurality of elastic bodies. The elastic body is arranged such that when the elastic body is compressed and deformed, the separation distance is shortened and the upper surface thereof is brought into close contact with the lower surface of the upper mold plate, and a desired neck portion is attached to the metal container. The metal container is expanded in all directions by a bending mold having a necking part inside thereof for shaping, and the mandrel provided inside the bending mold and moving downward as the upper mold plate descends. and a work holder that restrains the movement of the side wall from the inside thereof, and the acting force accompanying restoration of the elastic deformation between the lower pressurizing device and the elastic body is greater than that of the elastic body. A necking mold characterized in that the device is configured to have a constant value and a large value.