JPS6316823A - Manufacture of can drum - Google Patents

Abstract

PURPOSE:To efficiently form a can drum having an inclined part being free from a wrinkle in an opening end part, by forming plural stepped parts whose diameter becomes smaller gradually from the center side of a bottomed cylindrical can drum to the opening end, and thereafter, forming the stepped part to a flat inclined part from the inside and outside surfaces of the can drum. CONSTITUTION:Even if a difference between a can drum diameter W and an opening diameter WX of an opening end is remarkable, a small diameter part 9 of a multi-stage is formed, and thereafter, an outer die and an inner die of a roller forming device are rotated and pressed from the inside and outside surfaces of a can drum 1, and a flat inclined part 10 is formed. Accordingly, even if a can drum material which is hard and whose draw-in workability is inferior is used, since a sudden compressive strain is not given, no wrinkle is generated in the inclined part 10 and the opening end, and also, the opening diameter WX of a prescribed opening end can be formed continuously without changing a drum diameter W3 of the small diameter part 9 which has been formed in advance.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for making a can body used for beverage cans, etc., which is provided with a sloped portion at the front end.

(Prior Art) In recent years, deformed metal cans have come into widespread use due to the diversification of tastes.

As one type of can, a two-piece deformable can is known, which has a smooth slope where the diameter of the can body gradually decreases toward the opening of the can body. As a manufacturing method of this two-piece deformed can, patent application publication B [(57-501768 Publication I
As shown in FIG. 4A, a plurality of small diameter portions d with stepped portions C are formed by forming narrowing portions ③ on the opening side of the can Jla so that the opening of the can 111a can be seen. A method of bringing a processing roll e into contact with the can body from the outside and pressing the stepped portion C and the small diameter portion d inward with the processing roll e to form the inclined portion f as shown in Fig. 4B. is proposed.

However, when such a manufacturing method is used, the step C and the small diameter portion d on the opening side of the can body a are processed 0-rule e.
When pressing to form the sloped part f, the diameter of the opening of the end Q connected to the sloped part f is reduced inward by the pressing force of the processing roll e. That is, the multi-stage small diameter portion d is flattened and the opening diameter of the opening of the can body a is also reduced. In order to press the processing roll e to perform processing such as forming an inclination, a sudden and large pressing force is required on the processing roll e, and the processing roll e also needs to make complicated movements. Therefore, the apparatus becomes complicated, and furthermore, there is a problem that wrinkles are generated at the sloped part f and the opening end of the can body a due to the sudden and suppressing process, which impairs the appearance. Wrinkles appear particularly when the can body material is hard and has poor drawing workability, or when the amount of deformation during processing is large.

In order to avoid wrinkles caused by such a sudden and large pressing force, it is necessary to apply a large pressing force very gradually, which is disadvantageous in that manufacturing efficiency is extremely reduced.

(Problems to be Solved by the Invention) The present invention solves such conventional problems, and solves the problems of the prior art by providing a solution to the open end of a bottomed cylindrical can body for two-piece cans or three-piece cans with one open end closed. It is an object of the present invention to provide a method for efficiently manufacturing a can body having a smooth sloped portion without causing wrinkles.

(Means for Solving the Problems) The present invention has been made to solve the above-mentioned problems. In the method of forming a continuous inclined portion in which the diameter of the can body gradually becomes smaller, a plurality of intervals are provided at the front end of the can body from the center side of the can body to the front end side, and a plurality of intervals are formed in the order of distance from the open end side. A narrowing process is performed to form a plurality of small diameter portions having stepped portions having diameters smaller than the body diameters of adjacent narrowing portions from the center side of the can body toward the frontage end, and then formed at the open end. It is characterized in that a small diameter portion having a stepped portion is pressed by rolls from the inner and outer surfaces of the can body to form a flat inclined portion.

(Example) The present invention will be explained below with reference to the drawings.

1A to 1G show an example of the method for manufacturing a can body according to the present invention, and in this embodiment, a can II (1) as shown in FIG. 3 is shown.
) shows a method for forming a continuous inclined portion (10) in which the diameter of the can body gradually decreases toward the open end side.

In addition, the can body (1) used in this embodiment has the same can body diameter W from the open end side to the bottom (3) side before being squeezed as shown in Fig. 1A. It is a can body.

First, as shown in Figure 1B, the body (4) of the can body (1) is held in the turret feeder (25), and the bottom (3) is held in the holding part (27) of the holding bag @ (26). Can body (
1) At the frontage end (2), move the outer mold (16) of the first squeezing device (11) toward the center of the can body (1), and
The open end (2) of the can body (1) is fitted into the holding surface (19) of the guide part (18) of the squeezing device (11). Then the first
The inner mold (17) of the squeezing device (11) is advanced toward the center of the can body (1) and inserted into the open end (2) of the can body (1). Then again, the outer mold (1) of the first narrowing device ff1 (11)
6) toward the center of the can body (1), the can body (1)
The opening end (2) of the outer mold (16) is the step forming surface (22
), and then along the inner circumferential surface (21) of the molding part (20) of the outer mold (16), formed by this inner circumferential surface (21) and the outer periphery (23) of the inner mold (17). It is advanced to the end (24a) of the gap (24), and as a result, a stepped portion (
5) is formed.

Next, as shown in FIG. 1C, a first
The body part (4) of the can body (1) in which the small diameter part (6) is formed is held by a turret feeder (30), the bottom part (3) is held by a holding part (42) of a holding device (41), Can ri4 (1
) of the outer mold (3) of the second narrowing device (12).
1) to the center of the can body (1), and place the can body (1) on the holding surface (34) of the guide section (33) of the second squeezing device (12).
) is fitted with the first small diameter portion (6) of the open end (2).

Next, the inner mold (32) of the second squeezing device (12) is inserted into the can [4 (
1) and move it forward toward the center of the can IM (1) to open the can IM (1).
2) Insert it inside. And again the second narrowing device (12
) when the outer mold (31) of the can body (1) is advanced toward the center of the can body (1), the open end (2) of the can body (1) follows the step forming surface (37) of the outer mold (31), Next, the molding part (3) of the outer mold (31)
A gap (
39) to the end (39a) of the second
The first small diameter part (6) of the can 11 (1) shown in the figure has a stepped part (5 ) with a second small diameter section (7)
is formed.

Next, as shown in the first diagram, the body (4) of the can body (1) in which the first small diameter part (6) and the second small diameter part (7) were formed at the open end (2) in the previous process. is held by the turret feeder (50), and the bottom part (3) is held by the holding part (62) of the holding device (61).
The outer mold (51) of the third squeezing device (13) is moved toward the center of the can body (1) at the open end (2) of the can body (1), and the third squeezing device The second small diameter portion (2) of the open end (2) of the can body (1) is attached to the holding surface (54) of the guide portion (53) of (13).
7) are fitted. Next, the inner mold (52) of the third squeezing device (13) is advanced toward the center of the can body (1) to remove the can body (1).
into the open end (2) of the Then, when the outer mold (51) of the third squeezing device (13) is advanced toward the center of the can body (1), the open end (2) of the can body (1)
1) along the step forming surface (57), and then the outer mold (51)
The end (59a) of the gap (59) formed by the inner circumferential surface (56), the inner mold (52), and the outer circumferential surface (58) along the inner circumferential surface (56) of the molded part (55). As a result, the second small diameter portion (7) of the can body (1) as shown in the second figure is advanced.
), a third small diameter part (8) is formed with a step part (5) having a length L3 and a body diameter W3 smaller than that of the second small diameter part (7), with an interval toward the open end side.

Through the above steps, the open end of the can body (1) (
2) includes a plurality of small diameter portions (9) having step portions (5), and a third small diameter portion (having the same diameter as the opening diameter Wx of the predetermined opening end when forming the slope portion (10) described below). 8) A can IN(1) having a body diameter W3 is manufactured.

In order to form a smooth slope (10) at the open end (2) of the can body (1) as shown in Figure 3, first, the can body obtained in the previous step is (1) bottom (3)
is held by the holding part (77) of the holding device (76),
An outer mold (72) having an inclined portion forming surface (73) at the open end (2) of the held can body (1);
) with a shape corresponding to the slope forming surface (73) of
5) and an inner mold (14), the roll-formed @ (71) is advanced, and the roll-formed @ (71)
) is inserted into the open end (2) of the can body (1). Next, the inner mold (74) is made to face. Next, as shown in Figure 1F, the outer mold (72) of the O-ru molding device (71) is
) and the inner mold (74) are brought closer together.

Next, when the holding device (76) is rotated as shown in FIG. (74) and the forming surface (75) of the can l51 (1), the multi-stage small diameter part (9) of the open end (2) of the can l51 (1) is sequentially compressed over its entire circumference,
As shown in Figure 3, a predetermined opening diameter W is set at the open end of the can body (1).
A sloped portion (10
) to form.

Through the above steps, a can body (1) having an inclined portion (10) formed at the open end (2) of the can body (1) as shown in the third figure is manufactured.

In this case, even if the difference between the can body diameter W and the opening diameter Wx of the open end is significant, after forming the multi-stage small diameter portion (9), the roll forming device ( Since the flat sloped portion (10) is formed by pressing between the outer mold (72) and the inner mold (74) of 71), even if a hard can body material with poor drawing workability is used, there is no sudden change in the material. Since it does not apply compressive strain, it does not cause wrinkles on the inclined part (10) or the opening end, and the pre-formed small diameter part (
9) can be manufactured continuously and efficiently without changing the barrel diameter W3.

In the illustrated embodiment, a method is shown in which a slope is formed at the open end of a can body for a two-piece can. Similar methods and apparatus can be applied in forming ramps.

In each narrowing step for forming the small diameter portion (9) as in the above embodiment, if the diameter reduction rate for each narrowing step is made smaller than the diameter reduction rate before the narrowing step, a small diameter is formed at the opening end (2). There is no need to gradually increase the draw-forming pressure for forming the portion (9), and there is no possibility of wrinkles occurring in the stepped portion (5).

Moreover, the can body (1) obtained by this manufacturing method has an inclined part (
After the formation of step 10), a 7 flange portion is subsequently formed on the edge of the open end portion (2), and conventional methods and devices for forming flange portions can be used.

(Effects of the Invention) As described above, according to the present invention, steps are formed at the open end of the can body at a plurality of intervals from the center side of the can body to the open end side, with diameters smaller than the body diameter of the adjacent narrowing portions. The opening diameter of the opening end is formed to a predetermined diameter when forming the inclined part, and then the small diameter part including the stepped part formed at the opening end of the can body is formed into a can body. A bottomed cylindrical can body for a two-piece can or a three-piece can with one open end closed is manufactured by pressing the body with rolls from the inside and outside to form a flat inclined part. Therefore, we first formed a multi-stage small diameter section at the open end of the can body, and then pressed the multi-stage small diameter section from the inner and outer surfaces of the can body to form an inclined section. Even if there is a significant difference between the opening diameter and the opening diameter, it is possible to continuously and efficiently manufacture can bodies that have a predetermined opening diameter, have no wrinkles on the sloped portion or the opening end, and have an excellent appearance.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining one example of the manufacturing method of the present invention, FIG. 2 is a cutaway side view showing an example of a can body in the middle of the manufacturing method shown in FIGS. 1A to D, and FIG. The figure is a cutaway side view showing an example of a can body obtained by the manufacturing method shown in FIG. 1, and FIG. 4 is a partially cutaway side view of a conventional example. (1) Can body (2) Open end (5) Step part (9) Small diameter part (10) Slope part (B) 20\2118221925 27 y6 special Kaisho 6
3-IG823(5)

Claims (1)

[Claims] In a method of forming a continuous inclined part in which the diameter of the can body gradually decreases toward the open end side of the can body at the open end of a bottomed cylindrical can body, There are multiple intervals from the side to the open end side, and the narrowing process is performed multiple times in the order of distance from the open end side, and the diameter of the narrowed portions that are adjacent to each other from the center side of the can body toward the open end side is A plurality of small diameter portions having stepped portions having small diameters are sequentially formed, and then the small diameter portion including the stepped portion formed at the open end is pressed by a roll from the inner and outer surfaces of the can body to form a flat inclined portion. Characteristic can body manufacturing method.