JPH0476870B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a folding mechanism for a folding container that can change the outer diameter dimension and internal capacity (hereinafter referred to as bulk), and particularly relates to a folding mechanism for folding containers that can change the outer diameter dimension and internal capacity (hereinafter referred to as bulk). It is suitable for storing products and placing them in the distribution process, and then providing them in the maximum bulk state when used.

<Conventional technology> Being able to increase or decrease the volume of a container has many practical benefits such as cost savings during the distribution process, prevention of oxidation of contents, improvement of filling and sealing workability, prevention of seal breakage due to temperature changes, etc. A foldable container with variable volume is desirable because of its effectiveness.

However, for a foldable container to be placed in the distribution process and put to practical use, it must withstand at least the following four functions.

(1) Not only can the volume increase or decrease freely, but the maximum bulk state and the minimum bulk state are both stable, and when either is in one state, an external force that is applied due to the normal usage conditions of the container, For example, there is no risk of changing to another state easily due to load, vibration, shock, temperature change, pressure change, etc. Furthermore, it is possible to easily change the state described above even by manual manipulation, and furthermore, it will not become stable unless an external force is applied during the change of both states, and it will change by itself to a state close to either one and become stable. and that the change operation can be repeated repeatedly.

(2) In order to improve handling and productivity, the amount of change between the maximum bulk state and the minimum bulk state, especially the change in height, must be large.

(3) Containers that are easy to produce and do not change in bulk can be manufactured using the simplest and cheapest manufacturing method, such as vacuum or injection molding, a split cavity, or a sliding mechanism. It should be possible to mold the product in one step without the need for forced extraction or other operations.

(4) Raw materials can be either solid plastic materials or foam materials.

Unless a foldable container satisfies the above-mentioned four functions to the minimum necessary extent, it cannot be used during the distribution process or during use, so it has no value as a product.

Conventional collapsible containers that can change their volume include those disclosed in Japanese Patent Publication No. 57-7987 (hereinafter referred to as the 1st known example), JP-A-56-84246, and Utility Model Application Publication No. 60-8262 (hereinafter referred to as the 2nd example). Publicly known example), Utility Model Application No. 1973
Publication No. 134216, Japanese Utility Model Application Publication No. 58-14353 (hereinafter referred to as the third known example), and the like are known.

In the first known example described above, the bottom of the container is provided with an inclined surface and an inverted bottom, and bent portions are provided at the upper end of the inclined surface, the lower end of the body, and the lower end of the inclined surface and the periphery of the inverted bottom.

The above-mentioned second known example has a bellows part that expands and contracts in the vertical direction provided in a part of the body.

Further, in the above-mentioned third known example, a bellows portion that expands and contracts in the lateral direction is provided in a part of the body.

<Problems to be Solved by the Invention> Even with each of the above-mentioned folding containers, there are many drawbacks as described below.

Although it is recognized that the first known example was proposed to satisfy the function (1) mentioned above, it does not refract in practice unless the bent portion between the inclined surface and the inverted bottom is made sufficiently thin. The thickness of this bent part is at least one-third to one-fifth of the thickness of the trunk or inclined surface.
Therefore, if manufactured by vacuum forming, it is impossible to make the bent portions have the above-mentioned thickness. It is also possible to make the bent part protrude laterally to the above-mentioned thickness, but the mold does not come out when demolding, and the bent part must be crushed with a roller etc. to make it thinner after molding the container. Although it is possible to do so, productivity will be significantly reduced.

In the first known example, if the thickness of the bent part is not much different from that of the trunk, the rigidity is high, so there is a possibility that the inverted bottom can be restored to the maximum bulk state in the minimum bulk state without applying external force. Yes. Furthermore, even if an external force is applied to change the bulky state from the maximum bulky state to the minimum bulky state, the sloped surface may become distorted and break or be damaged. The internal stress of the part generates a force that restores the inverted bottom to its maximum bulk state,
There is a risk that stability will deteriorate or plastic deformation will occur, resulting in poor restorability in response to changes from the minimum bulk state to the maximum bulk state, and cracks may occur.

The purpose of the above-mentioned first known example is to prevent the contents from protruding out and interfere with the thermal bonding when the top surface is thermally sealed with a lid plate, and to reduce the internal air volume after sealing to reduce the pressure. The operation of the inverted bottom can be forcibly performed by external mechanical force, and after sealing, the inverted bottom will not return from the minimum bulk state to the maximum bulk state due to the internal reduced pressure state. Even if it does, there is no need to bring the inversion bottom to its maximum bulk state. Therefore, in the first known example, the above-mentioned configuration sufficiently achieves the intended purpose, but
Among the above-mentioned functions as a foldable container, some of (1), (2), (3), and (4) cannot be achieved.

The second known example is that when storing instant food inside a container, the volume of the food is minimized during the food filling or distribution stage because the moisture content is low, and the volume of the contents is increased by pouring boiling water when eating or drinking. However, since these two states are not stable, the container may swell during filling operations, or the bellows may crack during eating and drinking, causing hot water inside the container to leak. Moreover, since the bellows part prevents the mold from coming out during demolding, it is necessary to use a split mold, resulting in poor moldability. Therefore, among the above functions, (1), (3), and (4) cannot be achieved.

The third known example has a complicated structure, is low in productivity, lacks stability between the maximum bulk state and the minimum bulk state, and must be molded from a relatively flexible material. Therefore, among the functions described above, (1), (3), and (4) cannot be achieved.

<Means for Solving the Problems> The present invention has been proposed in view of the above, and includes forming a slope part in a part of the peripheral wall part, making the upper side part continuous above the slope part, and lowering the slope part downward. A container bending mechanism is provided on the side surface in which the side surface portion is continuous and the slope portion and the upper surface portion and the slope portion and the lower surface portion are connected by a bent portion that opens in the direction of movement of the mold during demolding. By partially configuring the foldable container, it is possible to achieve at least all of the above functions regardless of the structure or shape of the foldable container, and it is possible to achieve at least all the functions described above, whether in the filling process, the distribution process, or There is no problem during use, and it can be used practically.

<Example> A mechanism for bending a part of the side surface of a container according to the present invention will be explained below with reference to an example shown in the drawings.

FIG. 1 shows a longitudinal section of a foldable container 1 according to the present invention in its maximum bulk state. The top surface will be open.

The above-mentioned side wall portion 3 forms a slope portion 4 in a part of its height, and an upper side surface portion 5 is continuous above the slope portion 4, and a lower side surface portion 6 is continuous below the slope portion 4. . The upper edge of the slope portion 4 and the lower edge of the upper side surface portion 5 are connected at an upper bent portion 7 that opens in the direction of movement of the mold during demolding. It is connected to the upper edge at a lower bent portion 8 that opens in the direction of movement of the mold during demolding.

In the embodiment shown in the drawings, the upper bent portion 7 opens upward;
The lower bent portion 8 is open downward.

Each of the above-described upper bent portion 7 and lower bent portion 8 preferably has an upward or downward U-shape, and is preferably thinner than the side wall portion 3.

In order to change the foldable container 1 having the above configuration from the maximum bulk state to the minimum bulk state, an external force is applied from above to the top surface portion 5 or an external force is applied from below to the bottom surface portion 2.

To explain this changing state based on the principle shown in FIGS. 3a to 3c, the maximum outer diameter D ₀ and the minimum inner diameter d ₀ when the folding container 1 is in its maximum bulk state are the same as when the slope part 4 is horizontal during folding. The maximum outer diameter is
The diameter expands to D ₁ , and the minimum inner diameter decreases to d ₁ .
Since the lower part of the upper side part 5 expands outward and the upper part of the lower side part 6 contracts inwardly, these dimensional changes can be kept within the range of the elastic limit of the raw material and the external force applied during the folding operation. Must be set to . If the height exceeds this range, not only will the container be damaged or permanently deformed when folded, but it will also become difficult to manually fold the container. Therefore, if the upper bent portion 7 and lower bent portion 8 are not formed, the inversion angle θ, the radial length l, and the maximum folded height H of the slope portion 4 will be
The upper limit is determined by the raw materials used.

However, as in the present invention, the lower edge of the upper side surface part 5 and the upper edge of the slope part 4 are connected by the upper bent part 7, and the slope part 4
When the lower edge and the upper edge of the lower side surface part 6 are connected by the lower bent part 8, the upper bent part 7 and the lower bent part 8 elastically expand and contract when folded, as shown in FIGS. 4a to 4c. It is possible to increase the inversion angle θ and the length l in order to absorb the deformation of the side surface portion 5 and the lower side surface portion 6, and as a result, the maximum folded height H increases and the change in bulk can be increased. . Moreover, the upper bending portion 7
In the case of vacuum or air pressure molding, the raw material is locally stretched during molding, which inevitably makes the lower bent part 8 thinner.In the case of injection molding, the wall thickness of the lower bent part 8 can be reduced even without a special structure of the mold. Since it can be designed and molded, it has increased flexibility and can absorb the above-mentioned changes in shape and can be folded quickly.

The above-mentioned upper bent part 7 and lower bent part 8 have a function as a kind of hinge, so they need to be able to bend flexibly and not cause any cracks. It can be achieved.

Making the upper bent part 7 and the lower bent part 8 thinner can be easily formed by injection molding or vacuum forming because the upper bent part 7 and the lower bent part 8 are open in the direction of movement of the mold during demolding. , and there is no need to create a special structure for the type.

FIG. 5 shows another embodiment of the present invention, in which the upper bent part 7 and the lower bent part 8 are connected to a plurality of U-shaped parts 9.
It consists of a series of...

In this case, the U-shaped portions 9 adjacent to both the upper bent portion 7 and the lower bent portion 8 have alternately different opening directions, such as upward or downward, and have a horizontal meandering shape as a whole.

Therefore, since the length of the upper bent part 7 and the lower bent part 8 in the radial direction in this embodiment is longer than that of the upper bent part 7 and the lower bent part 8 of the above-described embodiment, the absorption function due to the shape change is increased. Not only can the amount of change in volume be increased, but even if the thicknesses of the upper bent portion 7 and lower bent portion 8 are made thicker than those of the previous embodiments, the flexibility will not be impaired.

FIG. 6 shows another embodiment of the present invention, in which the upper side part 5 is made sufficiently longer than the lower side part 6, and the slope part 4 is made closer to the bottom part 2. Further, in the embodiment shown in FIG. 7, contrary to the embodiment shown in FIG.
is positioned above.

In each of the embodiments described above, the upper side part 5 and the lower side part 6
The change in height between the maximum bulk state and the minimum bulk state is small by the difference in height between the two, but the substantial change in volume is large. Although the embodiment shown in FIG. 6 has relatively little content, it is effective for food products that require a sufficient supply of water or boiling water when eating or drinking. Further, the embodiment shown in FIG. 7 is effective for foods that have relatively large contents but do not require much water or boiling water to be added when eating or drinking.

In the embodiment shown in FIG. 8, two slopes 4, upper and lower, are formed on the side wall 3, and a middle side surface 10 is interposed between both slopes 4. An upper bent portion 7 between the lower edge of the upper side portion 5 and the upper edge of the upper slope portion 4, a lower bent portion 8 between the lower edge of the upper slope portion 4 and the upper edge of the middle side portion 10, and a lower bent portion 8 between the lower edge of the upper slope portion 4 and the upper edge of the middle side portion 10. The lower edge of the side surface portion 10 and the lower slope portion 4
The upper bent portion 7 with the upper edge and the lower bent portion 8 between the lower edge of the lower slope portion 4 and the upper edge of the lower side surface portion 6 are defined in the direction of movement of the mold during demolding, as in each of the above embodiments. It is open to the public.

Therefore, according to this embodiment, since it can be folded into two layers (upper and lower), the amount of change in volume is extremely large, and it is particularly effective for food products that have small contents but require a large amount of water or boiling water when eating or drinking. It is.

Note that in the embodiments shown in FIGS. 5 to 8, unexplained symbols have the same configuration as the same symbols in the embodiments shown in FIGS. 1 and 2, and therefore their explanation will be omitted.

Although the present invention has been described above with reference to the embodiments shown in the drawings,
The present invention is not limited to the embodiments described above, and can be implemented in any manner as long as the configurations described in the claims are not changed. For example, the slope part 4, the upper side part 5, the lower side part 6
Ribs may be formed on the folding container 1 to increase the strength of the entire folding container 1, and the slope portion 4 may be formed not only in one or two levels, but also in multiple levels. Further, the shape of the container is not limited to circular, but can also be quadrilateral, and the container may have any structure as long as it does not impair its function as a foldable container.

<Effects of the Invention> In summary, according to the present invention, a sloped portion is formed on a part of the peripheral wall, an upper side surface portion is continuous above the sloped portion, and a lower side surface portion is continuous below the sloped portion, and Since the upper side part and the slope part and the lower side part are connected by a bent part that opens in the direction of movement of the mold during demolding, both the maximum bulk state and the minimum bulk state are extremely stable. In either state, even if an external force is applied under normal usage conditions, it will not change to the other state, and if it is in the middle of both states, it will try to stabilize in a state close to either state. Therefore, when the contents are filled inside, the state does not change during the distribution process, during use, etc., making it practical.

In addition, the minimum bulk state is significantly smaller than conventional products, and the maximum bulk state can be increased, making it especially effective for handling during the distribution process.Furthermore, the raw materials are not specified, and molding is easy using the same molds as before. It can be produced at low cost and has high practical value.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a vertical cross-sectional view of the device in its maximum bulk state, FIG. 2 is a vertical cross-sectional view of FIG. 1 in its minimum bulk state, and FIGS. Figures 4a to 4c are principle views when folded, Figure 5 is a partially enlarged sectional view showing another embodiment of the present invention, and Figures 6 to 8 are longitudinal sections showing other embodiments of the present invention. It is a front view. 1 is a folding container, 3 is a side wall part, 4 is a slope part, 5
6 is the upper side, 7 and 8 are the bent parts.

Claims (1)

[Scope of Claims] 1. A sloped portion is formed in a part of the peripheral wall, an upper side surface portion is continuous above the sloped portion, and a lower side surface portion is continuous below the sloped portion, and the sloped portion, the upper side surface portion, and the sloped surface are continuous. A folding mechanism for a folding container in which a lower side part and a lower side part are connected by a bent part that opens in the direction of movement of the mold during demolding. 2 The bent part is a U that opens in the direction of movement of the mold during demolding.
The folding mechanism for a folding container according to claim 1, which has a letter shape. 3. The folding mechanism for a folding container according to claim 1 or 2, wherein the bending portion is thinner than the side wall portion.