JP7444545B2 - Container manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a container made of a sheet-like member such as paper, and more particularly to a method for manufacturing a container having a flat peripheral wall portion and a pleated portion formed by bending the peripheral wall portion. It is related to .

BACKGROUND ART Containers made of a sheet-like member such as paper, having a bottom portion, a peripheral wall portion, and an open top surface are widely used, for example, for storing food. A technique for manufacturing such a container is described in Patent Document 1.

The container covered by Patent Document 1 has an open top, a circular bottom, and a peripheral wall that stands up from the bottom, and the peripheral wall has a plurality of containers formed by bending linear bends extending in the upright direction. It has a shape in which folds are arranged at regular intervals. This pleated container is conventionally manufactured by a press molding method using a press molding device.

FIG. 15 is a sectional view showing a press molding apparatus for manufacturing containers.

The press molding device 1 includes a male mold 2 including a pressing part 3 and a drive shaft 4, and a female mold 5 having a cylindrical molding surface 7 and a molding space 6 with openings on one side 6a and the other side 6b. .

The pressing portion 3 of the male die 2 is configured to be movable forward and backward along the communication direction of the molding space 6 by a drive shaft 4 . The female mold 5 includes a female mold main part 8 having a tapered guide surface 8a on one side 6a, and extension parts 9A and 9B connected to the female mold main part 8 to extend the molding space 6 to the other side 6b. Be prepared.

Grooves m2 to m5 corresponding to the pleat shape of the container to be manufactured are formed in the guide surface 8a of the female mold main part 8 and the molding surface 7 of the female mold 5 so as to communicate from one side 6a to the other side 6b. has been done. A similar groove m1 is also formed in a portion of the male die 2 that corresponds to the guide surface 8a of the female die main portion 8.

Although not shown, a moving means for moving the male mold toward and away from the female mold is provided. Further, a heater is provided to heat each of the male and female molds, and a control means is provided to control the operation of the heater.

Manufacturing of a pleated container using this press molding apparatus 1 is performed through the following steps.

First, the male mold 2 and the female mold 5 are heated to an appropriate temperature using a heater.

Next, a blank is placed on one side 6a of the molding space 6 in the female mold 5. A blank is a sheet-like member formed to match the shape and size of a container to be manufactured, and usually, in order to manufacture a plurality of containers at the same time, a plurality of blanks are used in a stacked state.

Next, the male mold 2 is moved in the direction approaching the female mold 5 by the moving means, and a blank is sandwiched between the male mold 2 and the female mold 5, and this state is maintained for a certain period of time as necessary. As a result, the groove shapes of the grooves m1 and m2 are transferred to a portion of the blank corresponding to the peripheral wall portion.

Subsequently, with the blank sandwiched between the male mold 2 and the female mold 5, the pressing part 3 is moved toward the molding space 6 by the drive shaft 4 of the male mold 2, and the blank is pressed into the molding space 6. do. As a result, the portion of the blank corresponding to the bottom is pushed into the molding space 6, and at the same time, the portion corresponding to the peripheral wall contacts the molding surface 7 and stands up. At this time, the peripheral wall part is guided by the groove m3 of the molding surface and bent along the linear bending part extending in the upright direction, and a first blank molded body in which a large number of pleated parts are formed is molded. be done.

Subsequently, the male mold 2 is separated from the female mold 5, and a second blank is placed on one side 6a of the molding space 6 while the first blank molded body is held within the molding space 6. Then, the above-described process is performed again to form a second blank molded body so as to be stacked on the first blank molded body.

By repeating the above steps several times, blank molded bodies are accumulated in the molding space 6, but at this time, the blank molded body that has been molded earlier than the bottom of the blank molded body to be molded subsequently. As a result of the peripheral wall portion being pressed, the blank molded body moves within the molding space 6 from one side 6a to the other side 6b. Moreover, each blank molded body is heat-treated by the molding surface 7 while moving within the molding space 6, and its shape is fixed. The blank molded body is finally discharged from the other side 6b of the female mold 5 as a completed pleated container.

In addition, in Patent Document 1, the extension parts 9A and 9B are connected to the female mold main part 8 to ensure the heating time required for fixing the shape of the blank molded body.

Japanese Patent Application Publication No. 2006-315205

FIG. 16 is a plan view of a blank used for manufacturing conventional containers, FIG. 17 is a plan view of a blank used for manufacturing conventional containers of different shapes, and FIG. 18 is a plan view of a blank used for manufacturing conventional containers of different shapes. 19 is a diagram showing a conventional container manufactured using the blank of FIG. 17, in which (A) is a plan view, (B) is a front view, and (C) is a right side view; FIG. FIG. 3A is a plan view, (B) is a front view, and (C) is a right side view.

The container to be manufactured by the technique described in Patent Document 1 has a circular bottom and a peripheral wall having pleats formed at regular intervals over the entire circumference. Using this technique, a blank 50 whose outer periphery is a combination of an arcuate portion 52a and a linear portion 52b as shown in FIG. When manufacturing a container 53 in which the standing peripheral wall portion 55 has a shape having a flat planar portion 56 and a pleated portion 57 formed by bending the peripheral wall portion 55, or as shown in FIG. Using a blank 60 whose outer peripheral edge is a combination of a semicircular portion 62a and a linear portion 62b, a peripheral wall portion 65 rising from a bottom portion 64 is folded with a planar portion 66 as shown in FIG. When manufacturing a container 63 having a shaped portion 67, there is a problem in that the planar portion 56 (66) is deformed or crushed during the molding process. The reason for this will be explained using an example in which the container 53 in FIG. 18 is manufactured from the blank 50 in FIG. 16.

FIG. 20 is a diagram showing a blank molded body formed using the blank of FIG. 16, in which (A) is a plan view and (B) is a front view, and FIG. 21 illustrates problems with the conventional manufacturing method. FIG.

By pressing the blank 50, a blank molded body 58 as shown in FIG. 20 is obtained. In the conventional blank 50 shown in FIG. 16, the distance from the peripheral edge of the portion 52 corresponding to the peripheral wall to the portion 51 corresponding to the bottom is the same dimension d1 whether it is an arcuate portion 52a or a linear portion 52b. It is set as follows. Thereby, the blank molded body 58 is designed so that the planar portion 56 and the pleated portion 57 are at the same height. This blank molded body 58 is stored in a heated state in the molding space to fix its shape, and is moved within the molding space by pressing the bottom of the following blank molded body against the peripheral wall of the preceding blank molded body. . At this time, as shown in FIG. 21, if the blank molded body 58 is not molded as designed, the height of the peripheral wall portion 55 is not uniform, or the blank molded body 58 is not in an appropriate posture, the pressing Pressure may act on the planar portion 56, which has relatively low strength (buckling strength). As a result, if deformation occurs in the planar portion 56, the yield will decrease.

The same applies to the case where a conventional blank 60 shown in FIG. 17 is press-worked to produce a container 63 shown in FIG. The interval dimension is set to be the same dimension d2 in both the semicircular portion 62a and the linear portion 62b. Therefore, the blank molded body obtained in the molding process is designed so that the flat part and the pleated part are at the same height, so for the same reason as above, deformation occurs in the flat part 66, resulting in a lower yield. There is a problem that the amount decreases.

In addition, as in Patent Document 1, when the extension parts 9A and 9B are connected to the female mold main part 8 to secure the heating time required for fixing the shape of the blank molded body, there is no heat in the molding space 6. A plurality of blank molded bodies are stored, and since a large number of blank molded bodies are stacked on top of the blank molded bodies stored near the other side 6b of the molding space 6, the pressing force from the blank molded bodies located above is Deformation is also likely to occur due to repetition. Therefore, in order to increase the yield, it may be possible to increase the heating time by reducing the number of connected extension parts 9A and 9B and increasing the residence time of the blank molded body in the molding space 6, but in this case, the blank molded body The balance between the time required to form and the heating time becomes poor, and the time required to manufacture one container increases, resulting in a decrease in container productivity.

The object of the present invention is to prevent such crushing and deformation of the blank molded body and improve the yield without reducing productivity.

In order to achieve the above object, the method for manufacturing a container according to claim 1 includes a step of press-molding a blank made of a sheet-like member using a press-forming device to form a blank molded body, and then forming a container. A blank molded body has a bottom portion and a peripheral wall portion that stands up from the bottom portion, and the peripheral wall portion includes a planar portion that is formed flat and a linear bent portion that extends in the upright direction. The blank has a pleat-like portion formed by bending the peripheral wall portion along a flat surface, and the blank has a bottom surface equivalent portion corresponding to the bottom portion and a peripheral wall equivalent portion corresponding to the peripheral wall portion. The press forming apparatus has a flat part forming area corresponding to the shaped part and a pleated part forming area corresponding to the folded part, and the press forming apparatus includes a pressing means for pressing a portion corresponding to the bottom surface of the blank, and A first blank is provided with a molding surface that extends along the circumferential wall and defines an outer surface of the peripheral wall portion, and a molding space that is open on one side and the other side along the pressing direction, and a first blank is disposed on one side of the molding space. a second step of pushing the bottom surface portion of the first blank into the molding space by pressing the bottom surface portion of the first blank from one side of the molding space to the other side with the pressing means; By pushing the portion corresponding to the peripheral wall into contact with the molding surface and standing up against the portion corresponding to the bottom surface, and by bending the portion corresponding to the peripheral wall along a linear bending portion extending in the direction of standing up in the pleated portion forming region. A third step of forming a pleated portion to obtain a first blank molded body having a circumferential wall portion including a flat portion and a pleated portion, the first blank molded body being held in a molding space. In this state, the fourth step of arranging the second blank on one side of the molding space, the second step, and the third step are performed so that the second blank is stacked on top of the first blank molded product. A fifth step of forming a blank molded object, and by repeating the fourth step and the fifth step, the bottom part of the blank molded object to be molded subsequently forms the molding space previously molded. a sixth step of moving the blank molded object from one side to the other side in the molding space by pressing the peripheral wall of the blank molded object held within the molding space; The peripheral wall portion is formed such that the height from the bottom of at least a portion of the pleated portion is greater than the height from the bottom of the planar portion , and in the sixth step, the blank molding that is subsequently formed. The bottom of the body preferentially contacts the folds of the previously formed blank body .

With this configuration, by performing the first to sixth steps, a blank molded body having a bottom portion and a peripheral wall portion is continuously formed. In the first to third steps, the portion corresponding to the bottom of the sheet-like blank is pushed into the molding space, and the portion corresponding to the peripheral wall is brought into contact with the molding surface and erected, and at this time, the pleated portion forming area of the portion corresponding to the peripheral wall is By bending to form a pleated portion, a peripheral wall portion including a planar portion and a pleated portion is formed. The blank molded bodies formed sequentially in the fourth to sixth steps are moved from one side of the molding space to the other side by pressing the bottom of the subsequent blank molded body against the peripheral wall of the preceding blank molded body. , and will eventually be ejected from the other side. The peripheral wall portion of the blank molded body is formed such that the height from the bottom of at least a portion of the pleated portion is greater than the height from the bottom of the planar portion, so that the bottom of the subsequent blank molded body is It preferentially contacts the pleated portions of the preceding blank molded body.

The invention according to claim 2 is the structure of the invention according to claim 1, in which the peripheral wall portion of the blank molded body is formed such that the pleated portions are arranged at positions that are rotationally symmetrical with respect to the central axis of the bottom portion. , each pleated portion includes a portion whose height from the bottom is greater than the height from the bottom of the planar portion.

With this configuration, the plurality of pleated portions including portions higher than the planar portion are arranged at positions that are rotationally symmetrical with respect to the central axis of the bottom portion.

As explained above, the invention according to claim 1 provides that when pressing the peripheral wall portion of the preceding blank formed body with the bottom of the subsequent blank formed body, the pressing force is preferentially applied to the pleated portion having relatively high strength. This prevents or suppresses the pressing force from acting on the planar portion, which has relatively low strength, thereby preventing the blank molded body from being crushed or deformed, thereby improving the yield. At that time, since the basic manufacturing process is not changed, there is no risk of reducing productivity.

In addition to the effect of the invention as claimed in claim 1, the invention as claimed in claim 2 has the advantage that since the folded portion having a large height is arranged at a rotationally symmetrical position with respect to the central axis of the bottom, the subsequent folded portion is The posture of supporting the bottom of the blank molded body is stabilized, and deformation and crushing of the planar portion can be more reliably prevented.

(A) is a plan view of a blank according to the first embodiment of the present invention, and (B) is a partially enlarged plan view of this blank. 2 is a diagram showing a blank molded body formed using the blanks of FIG. 1, in which (A) is a plan view, (B) is a front view, and (C) is a partially enlarged front view in a stacked state. It is a figure which shows the container manufactured using the blank of FIG. 1, Comprising: (A) is a top view, (B) is a front view, and (C) is a right view. FIG. 2 is a cross-sectional view showing the manufacturing apparatus in a first step of the manufacturing method of the present invention. FIG. 3 is a cross-sectional view showing the manufacturing apparatus in a second step of the manufacturing method of the present invention. FIG. 3 is a cross-sectional view showing the manufacturing apparatus in a third step of the manufacturing method of the present invention. FIG. 7 is a sectional view showing the manufacturing apparatus in a fourth step of the manufacturing method of the present invention. It is a sectional view showing the manufacturing apparatus in a state of the fifth step of the manufacturing method of the present invention. FIG. 7 is a cross-sectional view showing the manufacturing apparatus in a state of a sixth step of the manufacturing method of the present invention. (A) is a plan view of a blank according to a second embodiment of the present invention, and (B) is a partially enlarged plan view of this blank. It is a figure which shows the blank molded object shape|molded using the blank of FIG. 10, Comprising: (A) is a top view, (B) is a front view. 11 is a diagram showing a container manufactured using the blank of FIG. 10, in which (A) is a plan view, (B) is a front view, and (C) is a right side view. (A) is a plan view of a blank according to a third embodiment of the present invention, and (B) is a partially enlarged plan view of this blank. (A) is a plan view of a blank according to a fourth embodiment of the present invention, and (B) is a partially enlarged plan view of this blank. FIG. 2 is a sectional view showing a press molding device for manufacturing containers. FIG. 2 is a plan view of a blank used in the manufacture of conventional containers. FIG. 2 is a plan view of a conventional blank used for manufacturing containers of different shapes. It is a figure which shows the conventional container manufactured using the blank of FIG. 16, Comprising: (A) is a top view, (B) is a front view, and (C) is a right view. It is a figure which shows the conventional container manufactured using the blank of FIG. 17, Comprising: (A) is a top view, (B) is a front view, and (C) is a right view. It is a figure which shows the blank molded object shape|molded using the blank of FIG. 16, Comprising: (A) is a top view, (B) is a front view. FIG. 2 is a partially enlarged cross-sectional view of a press molding device for explaining problems with the conventional manufacturing method.

[First embodiment]
FIG. 1A is a plan view of a blank according to the first embodiment of the present invention, FIG. 1B is a partially enlarged plan view of this blank, and FIG. FIG. 3 is a diagram showing a blank molded body formed by molding, (A) is a plan view, (B) is a front view, and (C) is a partially enlarged front view of a stacked state; FIG. 4 is a diagram showing a container manufactured using the method of the present invention, in which (A) is a plan view, (B) is a front view, and (C) is a right side view. FIG. 5 is a cross-sectional view showing the manufacturing apparatus in a process state, FIG. 5 is a cross-sectional view showing the manufacturing apparatus in a second step state of the manufacturing method of the present invention, and FIG. FIG. 7 is a cross-sectional view showing the manufacturing apparatus in the fourth step of the manufacturing method of the present invention, and FIG. FIG. 9 is a sectional view showing the manufacturing apparatus in the fifth step of the manufacturing method of the invention, and FIG. 9 is a sectional view showing the manufacturing apparatus in the sixth step of the manufacturing method of the invention.

In this embodiment, a blank 10A for manufacturing a container 30A (see FIG. 3) has a bottom surface equivalent part 11 corresponding to the bottom of the container and a peripheral wall equivalent part 12 corresponding to the peripheral wall part, as shown in FIG. The peripheral wall equivalent portion 12 has a planar portion forming region 12b corresponding to the planar portion and a pleated portion forming region 12a corresponding to the pleated portion. In this example, the portion with an arcuate edge is the pleated portion formation region 12a, and the portion with a straight edge is the planar portion formation region 12b. The pleated portion forming region 12a and the planar portion forming region 12b are formed by making the peripheral wall equivalent portion 12 stand up against the bottom surface equivalent portion 11 to form a blank molded body having a bottom portion and a peripheral wall portion (see FIG. 2). In this state, the region is set such that at least a portion of the pleated portion is higher than the planar portion.

Specifically, with reference to FIG. 1B, the distance D1 from the edge of the pleated portion forming region 12a to the bottom surface equivalent portion 11 is determined by the distance D1 from the edge of the planar portion forming region 12b to the bottom surface. The distance is set to be larger than the distance D2 to the corresponding portion 11. In the conventional blank, the arcuate portion 14 at the end edge of the peripheral wall equivalent portion 12 is a concentric circle having a common center at point P1 with the arcuate portion 13 at the outer edge of the bottom surface equivalent portion 11, and the peripheral wall equivalent portion 12 The linear portion at the edge of is set to be parallel to the linear portion of the outer edge of the bottom surface equivalent portion 11, and the distance dimension D2 from the edge portion of the peripheral wall equivalent portion 12 to the bottom surface equivalent portion 11 is constant. On the other hand, in the blank 10A of this example, the center of the circular arc portion forming the edge of the pleated portion forming region 12a is set on the circular arc portion 13 at the outer edge of the bottom surface equivalent portion 11, and the radius is set as above. It is assumed to be set to D1.

Next, a method for manufacturing a container using this blank 10A will be explained. Since the press molding apparatus 1 shown in FIG. 15 is used here, description regarding the structure of the press molding apparatus 1 will be omitted. Note that the pressing section 3 of the press molding device 1 corresponds to a pressing means for pressing the bottom surface equivalent portion 11 of the blank 10A. Further, the blank 10A is made of a sheet-like member such as paper, plastic film, or metal foil. When manufacturing a plurality of products at the same time, a plurality of blanks 10A are used in a stacked state.

First, if necessary, the male mold 2 and the female mold 5 are heated to an appropriate temperature using a heater or the like.

Next, as shown in FIG. 4, a blank 10A is placed on one side 6a of the molding space 6 in the female mold 5 (first step).

Subsequently, as shown in FIG. 5, the male die 2 is moved in the direction approaching the female die 5 using a moving means (not shown) (second step), and a blank 10A is placed between the male die 2 and the female die 5. By holding this state for a certain period of time as necessary, the groove shapes of the grooves m1 and m2 are transferred to the pleated portion forming region 12a.

Subsequently, with the blank 10A sandwiched between the male mold 2 and the female mold 5, the pressing part 3 is moved toward the molding space 6 by the drive shaft 4 of the male mold 2, and the blank 10A is moved into the molding space 6. Press towards. As a result, the bottom surface equivalent part 11 of the blank 10A is pushed into the molding space 6, and at the same time, the peripheral wall equivalent part 12 comes into contact with the molding surface 7 and stands up, resulting in a first blank molded product 20A as shown in FIG. is formed. At this time, the pleated portion forming region 12a is bent along the linear bending portion extending in the upright direction, guided by the groove m3 of the molding surface, and as a result, as shown in FIG. A peripheral wall portion 22 including 23 and a pleated portion 24 is formed (third step).

At this time, the blank 10A has a distance D1 from the edge of the pleated portion forming region 12a to the bottom surface equivalent portion 11 than a distance D2 from the edge of the planar portion forming region 12b to the bottom surface equivalent portion 11. Since the height H1 of at least a portion of the pleated portion 24 is set to be larger than the height H2 of the planar portion 23 in the molded state of the blank molded body 20A (( See B).

Subsequently, as shown in FIG. 7, while the male mold 2 is separated from the female mold 5 and the first blank molded body 20A is held in the molding space 6, a second mold is placed on one side 6a of the molding space 6. Place the blank 10A (fourth step).

Then, as shown in FIG. 8, the above-described steps are performed again to form a second blank molded body 20A so as to be stacked on the first blank molded body 20A (fifth step).

By repeating the above steps several times, a plurality of blank molded bodies 20A are accumulated in the molding space 6, as shown in FIG. 9 (sixth step).

At this time, the peripheral wall portion 22 of the previously molded blank molded body 20A is pressed by the bottom portion 21 of the blank molded body 20A to be molded subsequently, so that the blank molded body 20A moves inside the molding space 6 on one side 6a. from there to the other side 6b. In this example, as shown in FIGS. 2B and 2C, the height H1 from the bottom 21 of at least a portion of the pleated portion 24 in the blank molded body 20A is the height H1 from the bottom 21 of the planar portion 23. Since the height is larger than the height H2, the bottom part 21 of the blank molded body 20A to be molded subsequently comes into preferential contact with the pleated portion 24 of the blank molded body 20A molded previously. become. As a result, when the subsequent blank molded body presses the preceding blank molded body, the pressing force acts preferentially on the pleated portions with relatively high strength (buckling strength), and on the flat portions with relatively low strength. can be avoided or suppressed. As a result, the blank molded body is prevented from being crushed or deformed, and the yield can be improved.

Thereafter, each blank molded body is heated by the molding surface 7 while moving within the molding space 6, and its shape is fixed. The blank molded body is finally discharged from the other side 6b of the female mold 5, and a container 30A as shown in FIG. 3 is manufactured.

In this example, since the strength against pressing force (buckling strength) of the blank molded body is improved, the number of extension parts 9A and 9B connected to the female mold main part 8 is increased to reduce the heating time of the blank molded body. Since it can be made longer, it is possible to process at a lower temperature than before. Furthermore, even when the heating temperature is the same as before, by increasing the number of extensions 9A and 9B, the heating time required to fix the shape of the blank molded body can be secured, so the time required to form the blank molded body and the time required to form the blank molded body can be reduced. The balance with heating time is improved, and the productivity of containers is improved.

[Second embodiment]
FIG. 10(A) is a plan view of a blank according to the second embodiment of the present invention, FIG. 10(B) is a partially enlarged plan view of this blank, and FIG. FIG. 12 is a diagram showing a blank molded body formed using the blank shown in FIG. 10, where (A) is a plan view and (B) is a front view; (A) is a plan view, (B) is a front view, and (C) is a right side view.

The blank 10B shown in FIG. 10 corresponds to the conventional blank 60 shown in FIG. 17, and is for manufacturing the container 30B shown in FIG. 12.

Also in this blank 10B, the peripheral wall equivalent portion 12 corresponding to the peripheral wall portion includes pleated portion forming regions 12a and 12c corresponding to the pleated portions, and a planar portion forming region 12b corresponding to the planar portion. However, the fold-forming region in this example includes a region (12a) with an arc-shaped end edge and a short linear region (12c). The pleated portion forming regions 12a, 12c and the planar portion forming region 12b are formed in a state in which the peripheral wall equivalent portion 12 is made to stand up against the bottom surface equivalent portion 11 to form a blank molded body having a bottom portion and a peripheral wall portion. At least a portion of the pleated portion is set to be higher than the planar portion. Specifically, with reference to FIG. 10(B), the distance D3 from the edge portions of the pleated portion forming regions 12a, 12c to the bottom surface equivalent portion 11 is equal to the distance D3 from the edge portion of the planar portion forming region 12b. It is set larger than the interval dimension D4 from to the bottom surface equivalent part 11. In the conventional blank, the arcuate portion 14 at the end edge of the peripheral wall equivalent portion 12 is a concentric circle having a common center at point Q1 with the arcuate portion 13 at the outer edge of the bottom surface equivalent portion 11; The linear portion of the edge portion is set to be parallel to the linear portion of the outer edge portion of the bottom surface equivalent portion 11 . On the other hand, in the blank 10B of this example, the center Q2 of the circular arc portion at the edge of the pleated portion forming region 12a is outside the center Q1 of the circular arc portion 13 at the outer edge of the bottom surface equivalent portion 11. The radius R is set so that the distance dimension D3 is larger than the distance dimension D4.

With such a setting, it is possible to make at least a portion of the pleated portion 24 higher than the planar portion 23 in a state in which the blank molded body 20B (see FIG. 11) is molded.

[Third embodiment]
FIG. 13(A) is a plan view of a blank according to the third embodiment of the present invention, and FIG. 13(B) is a partially enlarged plan view of this blank.

In the blank 10C of this example, by changing the curvature of the arcuate portion 13 in the bottom surface equivalent portion 11 from that of the conventional one, the distance dimension D5 from the edge of the pleated portion forming region 12a to the bottom surface equivalent portion 11 is changed from that in the planar portion. This is set to be larger than the distance D6 from the edge of the formation region 12b to the bottom surface equivalent portion 11.

With this configuration as well, it is possible to form at least a portion of the pleated portions higher than the planar portions when the blank molded body is molded.

[Fourth embodiment]
FIG. 14(A) is a plan view of a blank according to the fourth embodiment of the present invention, and FIG. 14(B) is a partially enlarged plan view of this blank.

The blank 10D of this example is formed by curving the edge of the planar portion forming region 12d adjacent to the pleat forming region 12a having an arcuate edge toward the bottom surface equivalent portion 11. The distance D7 from the edge of the forming area 12a to the bottom equivalent part 11 is set to be larger than the distance D8 from the edge of the planar part forming area 12d to the bottom equivalent part 11. .

With this configuration as well, it is possible to form at least a portion of the pleated portions higher than the planar portions when the blank molded body is molded.

The drawings show a case in which the peripheral wall is bent to protrude outward from the flat part to form a pleated part, but conversely, the peripheral wall can be folded inward from the flat part to form a pleated part. It may also form a part.

The pleated portions are preferably arranged rotationally symmetrically with respect to the central axis of the bottom, but may also be arranged asymmetrically depending on the shape of the container.

It is sufficient that at least a portion of the pleated portion is higher than the planar portion, but the entire portion may be higher. Alternatively, the high portions can be formed intermittently.

1... Press molding device 2... Male mold 3... Pressing part (pressing means)
4... Drive shaft 5... Female mold 6... Molding space 6a... One side 6b... Other side 7... Molding surface 10A to 10D... Blank 11... Bottom surface equivalent part 12... Peripheral wall equivalent part 12a, 12c... Folded portion forming area 12b, 12d...Planar part forming area 20A, 20B...Blank molded body 21...Bottom part 22...Peripheral wall part 23...Planar part 24...Folded part 30A, 30B...Container Note that the same reference numerals in each figure indicate the same or equivalent parts. .

Claims (2)

A method for manufacturing a container through a step of forming a blank formed body by press forming a blank made of a sheet-like member using a press forming apparatus, the method comprising:
The blank molded body has a bottom part and a peripheral wall part that stands up from the bottom part, and the peripheral wall part has a flat planar part and a linear bent part that extends in the upright direction. and a pleated portion formed by folding the portion,
The blank has a bottom surface equivalent part corresponding to the bottom part and a peripheral wall equivalent part corresponding to the peripheral wall part, and the peripheral wall equivalent part has a planar part forming area corresponding to the planar part and the pleated part. and a fold-shaped portion forming region corresponding to the
The press molding device includes a pressing means for pressing a portion corresponding to the bottom surface of the blank, a molding surface extending along a pressing direction of the pressing means and defining an outer surface of the peripheral wall portion, and a molding surface that extends along a pressing direction of the pressing means and defining an outer surface of the peripheral wall portion. and a molding space that is open on one side and the other side,
a first step of arranging the first blank on the one side of the molding space;
a second step of pushing the bottom surface equivalent portion of the first blank into the molding space by pressing the bottom surface equivalent portion of the first blank from the one side to the other side of the molding space with the pressing means;
By pushing the portion corresponding to the bottom surface into the molding space, the portion corresponding to the peripheral wall comes into contact with the molding surface and stands up with respect to the portion corresponding to the bottom surface, and a line extends in the rising direction in the pleated portion forming region. The first blank molded body has the peripheral wall portion including the planar portion and the pleated portion formed by forming the pleated portion by bending the portion corresponding to the peripheral wall along the bent portion of the shape. The third step of obtaining
a fourth step of arranging the second blank on the one side of the molding space while the first blank molded body is held in the molding space;
a fifth step of forming a second blank molded body so as to be stacked on the first blank molded body by performing the second step and the third step, and
By repeating the fourth step and the fifth step, the bottom part of the blank molded object to be molded subsequently is used to remove the bottom part of the blank molded object that was previously molded and held in the molding space. a sixth step of pressing a peripheral wall portion to move the blank molded body from the one side to the other side in the molding space,
In the third step, the peripheral wall portion of the blank molded body is formed such that the height of at least a portion of the pleated portion from the bottom portion is greater than the height of the planar portion from the bottom portion. is,
In the sixth step, the bottom of the blank molded body that is subsequently molded comes into preferential contact with the pleated portion of the blank molded body that is molded previously. The peripheral wall portion of the blank molded body is formed such that the pleated portions are arranged at positions that are rotationally symmetrical to each other with respect to the central axis of the bottom portion, and each of the pleated portions has a height from the bottom portion. The method for manufacturing a container according to claim 1, further comprising a portion having a height greater than the height of the planar portion from the bottom .

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